FORM 2
THE PATENTS ACT, 1970
As amended by the Patents (Amendment) Act, 2002
and
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules 2016
COMPLETE SPECIFICATION
(Section 10 and Rule 13)
TITLE OF THE INVENTION NOVEL FORMULATIONS
APPLICANTS
ARECOR LIMITED, a British company, having its address at Chesterford Research Park,
Little Chesterford, Saffron Walden Cambridgeshire CB10 1XL, Great Britain
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed

FIELD OF THE INVENTION
This invention relates inter alia to rapid acting aqueous liquid formulations of insulin and insulin analogues. Such compositions are suitable for the treatment of subjects suffering from diabetes mellitus, especially Type I diabetes mellitus.
BACKGROUND OF THE INVENTION
Diabetes mellitus (“diabetes”) is a metabolic disorder associated with poor control of blood sugar levels leading to hypo or hyperglycaemia. Untreated diabetes can lead to serious microvascular and macrovascular complications including coronary artery disease, peripheral artery disease, stroke, diabetic nephropathy, neuropathy and retinopathy. The two main types of diabetes are (i) Type 1 diabetes resulting from the pancreas not producing insulin for which the usual treatment is insulin replacement therapy and (ii) Type 2 diabetes where patients either produce insufficient insulin or have insulin resistance and for which treatments include insulin sensitising agents (such as metformin or pioglitazone), traditional insulin secretagogues (such as sulfonylureas), SGLT2 inhibitors (such as dapagliflozin, canagliflozin and empagliflozin) which reduce glucose absorption in the kidneys and so promote glucose excretion, GLP-1 agonists (such as exenatide and dulaglutide) which stimulate insulin release from pancreatic beta cells and DPPIV inhibitors (such as sitagliptin or vildagliptin) which inhibit breakdown of GLP-1 leading to increased insulin secretion. Patients with Type 2 diabetes may eventually require insulin replacement therapy.
For patients requiring insulin replacement therapy, a range of therapeutic
options are possible. The use of recombinant human insulin has in recent times been
overtaken by use of insulin analogues which have modified properties, for example, are
longer acting or faster acting than normal insulin. Thus, a common regimen for a
patient involves receiving a long acting basal insulin supplemented by a rapid acting insulin around mealtimes.
Insulin is a peptide hormone formed of two chains (A chain and B chain, respectively 21 and 30 amino acids in length) linked via disulfide bridges. Insulin normally exists at neutral pH in the form of a hexamer, each hexamer comprising three dimers bound together by zinc ions. Histidine residues on the insulin are known to be involved in the interaction with the zinc ions. Insulin is stored in the body in the

hexameric form but the monomer form is the active form. Traditionally, therapeutic compositions of insulin have also been formulated in hexameric form in the presence of zinc ions. Typically, there are approximately three zinc cations per one insulin hexamer. It has been appreciated that the hexameric form is absorbed from the injection site considerably more slowly than the monomeric and dimeric forms. Therefore, a faster onset of insulin action can be achieved if the hexameric form is destabilised allowing a more rapid dissociation of the zinc-bound hexamer into dimers and monomers in the subcutaneous space following injection. Three insulin analogues have been genetically engineered with this principle in mind. A first is insulin lispro (Humalog®) in which residues 28 and 29 of the B chain (Pro and Lys respectively) are reversed, a second is insulin aspart (NovoRapid®/NovoLog®) in which residue 28 of the B chain, normally Pro, is replaced by Asp, and a third is insulin glulisine (Apidra®) in which residue 3 of the B chain, normally Asn, is replaced by Lys and residue 29 of the B chain, normally Lys, is replaced by Glu.
Whilst the existing rapid acting insulin analogues can achieve a more rapid onset
of action, it has been appreciated that even more rapid acting (“ultra rapid acting”)
insulins can be achieved by removing the zinc cations from insulin altogether.
Unfortunately, the consequence of the hexamer dissociation is typically a considerable
impairment in insulin stability both with respect to physical stability (e.g. stability to
aggregation) and chemical stability (e.g. stability to deamidation). For example,
monomeric insulin or insulin analogues having a rapid onset of action are known to
aggregate and become physically unstable very rapidly because the formulation of
insoluble aggregates proceeds via monomers of insulin. Various approaches to
addressing this problem have been described in the art:
US5,866,538 (Norup) describes insulin preparations of superior chemical stability comprising human insulin or an analogue or derivative thereof, glycerol and/or mannitol and 5 mM to 100 mM of a halogenide (e.g. NaCl).
US7,205,276 (Boderke) addresses the stability problems associated with preparing zinc-free formulations of insulin and insulin derivatives and analogues and describes an aqueous liquid formulation comprising at least one insulin derivative, at least one surfactant, optionally at least one preservative and optionally at least one of an isotonicizing agent, a buffer and an excipient, wherein the formulation is stable and

free from or contains less than 0.4% (e.g. less than 0.2%) by weight of zinc based on the insulin content of the formulation. The preferred surfactant appears to be polysorbate 20 (polyoxyethylene (20) sorbitan monolaurate).
US2008/0194461 (Maggio) describes formulations of peptides and polypeptides including insulin which contain an alkyl glycoside, which component is said to reduce aggregation and immunogenicity.
WO2012/006283 (Pohl) describes formulations containing insulin together with a zinc chelator such as ethylenediaminetetraacetate (EDTA). Modulating the type and quantity of EDTA is said to change the insulin absorption profile. Calcium EDTA is the preferred form of EDTA since it is said to be associated with reduced pain at the injection site and is less likely to remove calcium from the body. Preferred formulations also contain citrate which is said to further enhance absorption and to improve the chemical stability of the formulation.
US2010/0227795 (Steiner) describes a composition comprising insulin, a dissociating agent such as citric acid or sodium citrate, and a zinc chelator such as EDTA wherein the formulation has a physiological pH and is a clear aqueous solution. The formulations are said to have improved stability and rapid onset of action.
WO2015/120457 (Wilson) describes stabilized ultra-rapid acting insulin formulations comprising insulin in combination with a zinc chelator such as EDTA, a dissolution/stabilization agent such as citric acid, a magnesium salt, a zinc compound and optionally additional excipients.
Further approaches to accelerating the absorption and effect of insulin through the use of specific accelerating additives have been described:
WO91/09617 (Jørgensen) reports that nicotinamide or nicotinic acid or a salt thereof increases the speed of absorption of insulin from aqueous preparations administered parenterally.
WO2010/149772 (Olsen) describes a formulation comprising insulin, a nicotinic compound and arginine. The presence of arginine is said to improve the chemical stability of the formulation.
WO2015/171484 (Christe) describes rapid-acting formulations of insulin wherein onset of action and/or absorption of insulin is faster due to the presence of treprostinil.

US2013/0231281 (Soula) describes an aqueous solution composition comprising insulin or an insulin analogue and at least one oligosaccharide whose average degree of polymerisation is between 3 and 13 and whose polydispersity index is above 1.0, said oligosaccharide having partially substituted carboxyl functional groups, the unsubstituted carboxyl functional groups being salifiable. Such a formulation is said to be rapid acting.
PCT/GB2017/051254 (Arecor Limited) describes an aqueous liquid pharmaceutical formulation comprising insulin or an insulin analogue, ionic zinc, a chelating agent and polysorbate 80.
WO2016/100042 (Eli Lilly and Company) describes a composition of human insulin or insulin analogue that includes specific concentrations of citrate, chloride, in some cases including the addition of sodium chloride, zinc and, optionally magnesium chloride and/or surfactant, said to have faster pharmacokinetic and/or pharmacodynamic action than commercial formulations of existing insulin analogue products.
Commercially available rapid-acting insulin formulations are available as 100 U/ml formulations (Humalog® (insulin lispro), NovoRapid® (also known as NovoLog®, insulin aspart) and Apidra® (insulin glulisine)) and 200 U/ml formulations (Humalog®). Formulations having a higher concentration of insulin compound are desirable e.g. for patients that require higher insulin doses, such as obese patients or patients who have developed insulin resistance. Formulations having a higher concentration of insulin are thus desirable for these categories of patients as the required high dose can be delivered in a smaller volume. Whilst the development of the 200 U/ml Humalog® formulation was an important step toward patient convenience in the situations described above, there remains a strong need to develop formulations of rapid-acting insulins at considerably higher concentrations, such as 500 U/ml or 1000 U/ml whilst maintaining the rapid onset of action.
However, a known problem associated with the use of formulations containing higher concentrations of insulin compound, in particular rapid-acting insulin compounds, is that the rapid-acting effects observed at low concentration (or low strength) formulations e.g. 100 U/ml of insulin compound, are reduced. Thus, increasing the concentration of insulin compound has been observed to lead to a slower onset of

action even if the same dose is delivered, see for example de la Peña et al. Pharmacokinetics and Pharmacodynamics of High-Dose Human Regular U-500 Insulin Versus Human Regular U-100 Insulin in Healthy Obese Subjects, Diabetes Care, 34, pp 2496-2501, 2011.
It would be desirable if analogues or formulations of insulin were available which were ultra-rapid acting, thus more closely matching the activity of physiological insulin. There also remains a need in the art to provide further, and preferably improved, formulations of insulin and insulin analogues which are rapid acting and stable. Furthermore, there is a need to provide formulations of higher concentration of insulin compound, wherein the speed of onset of action of the insulin compound is maintained.
SUMMARY OF THE INVENTION
According to the invention there is provided an aqueous liquid pharmaceutical formulation comprising (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C, and (iv) a non-ionic surfactant which is an alkyl glycoside; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C (“the formulation of the invention”). In some embodiments, the alkyl glycoside is dodecyl maltoside. In further embodiments, the zinc binding species is citrate.
The formulations of the invention provide insulin in a form which is rapid or ultra-rapid acting with good physical and chemical stability. As noted in the background discussion above, use of EDTA to chelate zinc ions in hexameric insulin does increase the rapidity of action but at the cost of greatly reduced stability. Without being limited by theory, the present inventors have appreciated that the use of zinc together with species which bind zinc less strongly can achieve similar effects in terms of speed of action and their moderately destabilising effects can be reduced or eliminated by using a non-ionic surfactant which is an alkyl glycoside.

Formulations of the invention may be used in the treatment of subjects suffering from diabetes mellitus, particularly Type 1 diabetes mellitus especially for administration at meal times.
As can be seen from the accompanying examples, formulations of the invention are significantly more stable than corresponding formulations without non-ionic surfactant. The formulations achieve a rapid speed of action of insulin and are more stable than prior art rapid acting insulin formulations containing EDTA.
DESCRIPTION OF THE SEQUENCE LISTING SEQ ID NO: 1: A chain of human insulin SEQ ID NO: 2: B chain of human insulin SEQ ID NO: 3: B chain of insulin lispro SEQ ID NO: 4: B chain of insulin aspart SEQ ID NO: 5: B chain of insulin glulisine
FIGURES
Fig. 1. Pharmacodynamic profiles of Formulations 1-3 of Example 4 in a validated
diabetic Yucatan miniature pig model.
Fig. 2. Pharmacodynamic profile of Formulations 13A and 13B of Example 13 in a validated diabetic Yucatan miniature pig model.
Fig. 3. Pharmacodynamic profiles of formulations 14A-14D of Example 14 in a validated diabetic Yucatan miniature pig model.
Fig. 4. Pharmacokinetic profiles of formulations 14A-14C of Example 14 in a validated diabetic Yucatan miniature pig model.
Fig. 5. Pharmacodynamic profiles of formulations 15A-15D of Example 15 in a validated diabetic Yucatan miniature pig model.

Fig. 6. Pharmacokinetic profiles of formulations 15A, 15B and 15D of Example 15 in a validated diabetic Yucatan miniature pig model.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, “insulin compound” refers to insulin and insulin analogues.
As used herein, “insulin” refers to native human insulin having an A chain and a B chain as set out in SEQ ID NOs. 1 and 2 and containing and connected by disulfide bridges as in the native molecule (Cys A6-Cys A11, Cys B7 to Cys A7 and Cys-B19-Cys A20). Insulin is suitably recombinant insulin.
“Insulin analogue” refers to an analogue of insulin which is an insulin receptor agonist and has a modified amino acid sequence, such as containing 1 or 2 amino acid changes in the sequence of the A or B chain (especially the B chain). Desirably such amino acid modifications are intended to reduce affinity of the molecule for zinc and thus increase speed of action. Thus, desirably an insulin analogue has a speed of action which is the same as or preferably greater than that of insulin. The speed of action of insulin or an insulin analogue may be determined in the Diabetic Pig Pharmacokinetic/Pharmacodynamic Model (see Examples, General Methods (c)). Exemplary insulin analogues include faster acting analogues such as insulin lispro, insulin aspart and insulin glulisine. These forms of insulin have the human insulin A chain but variant B chains – see SEQ ID NOs. 3-5. Further faster acting analogues are described in EP0214826, EP0375437 and EP0678522 the contents of which are herein incorporated by reference in their entirety. Suitably, the insulin compound is not insulin glargine. Suitably, the insulin compound is not insulin degludec. Suitably, the insulin compound is a rapid-acting insulin compound, wherein “rapid-acting” is defined as an insulin compound which has a speed of action which is greater than that of native human insulin e.g. as measured using the Diabetic Pig Pharmacokinetic/Pharmacodynamic Model (see Examples, General Methods (c)).
In one embodiment, the insulin compound is recombinant human insulin. In another embodiment, it is insulin lispro. In another embodiment, it is insulin aspart. In another embodiment, it is insulin glulisine.
The term “aqueous liquid pharmaceutical formulation”, as used herein, refers to a formulation suitable for therapeutic use in which the aqueous component is or

comprises water, preferably distilled water, deionized water, water for injection, sterile
water for injection or bacteriostatic water for injection. The aqueous liquid
pharmaceutical formulations of the invention are solution formulations in which all components are dissolved in water.
The concentration of insulin compound in the formulation will typically be in the range 10-1000 U/ml, such as 50-500 U/ml e.g. 50-200 U/ml. An exemplary formulation contains insulin compound at a concentration of 100 U/ml (around 3.6 mg/ml). Another range of interest is 500-1000 U/ml e.g. 800-1000 U/ml and another exemplary formulation contains insulin compound at a concentration of 1000 U/ml (around 36 mg/ml). Another range of interest is 50-1000 U/ml.
In one embodiment, the concentration of insulin compound in the formulation is 10-500 U/ml e.g. 10-<500 U/ml, 20-500 U/ml, 20-<500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml or 100-<500 U/ml. In one embodiment, the concentration of insulin compound in the formulation is 10-400 U/ml e.g. 10 to <400 U/ml, 20-400 U/ml, 20-<400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml or 100-<400 U/ml. In one embodiment, the concentration of insulin compound in the formulation is 10-300 U/ml e.g. 10-<300 U/ml, 20-300 U/ml, 20-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml or 100-<300 U/ml. In one embodiment, the concentration of insulin compound in the formulation is 10-250 U/ml e.g. 10-<250 U/ml, 20-250 U/ml, 20-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml or 100-<250 U/ml. In one embodiment, the concentration of insulin compound in the formulation is 10-200 U/ml e.g. 10-<200 U/ml, 20-200 U/ml, 20-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml or 100-<200 U/ml. In one embodiment, the concentration of insulin compound in the formulation is 10-100 U/ml, e.g. 10-<100 U/ml, 20-100 U/ml, 20-<100 U/ml, 50-100 U/ml or 50-<100 U/ml.
In one embodiment, the concentration of insulin compound in the formulation is 400-1000 U/ml e.g. >400-1000 U/ml. In one embodiment, the concentration of insulin compound in the formulation is 500-1000 U/ml e.g. >500-1000 U/ml. In one embodiment, the concentration of insulin compound in the formulation is 600-1000 U/ml, e.g. >600-1000 U/ml. In one embodiment, the concentration of insulin compound in the formulation is 700-1000 U/ml e.g. >700-1000 U/ml. In one embodiment, the concentration of insulin compound in the formulation is 750-1000 U/ml e.g. >750-1000

U/ml. In one embodiment, the concentration of insulin compound in the formulation is 800-1000 U/ml e.g. >800-1000 U/ml. In one embodiment, the concentration of insulin compound in the formulation is 900-1000 U/ml e.g. >900-1000 U/ml.
“U/ml” as used herein describes the concentration of insulin compound in terms of a unit per volume, wherein “U” is the international unit of insulin activity (see e.g. European Pharmacopoeia 5.0, Human Insulin, pp 1800-1802).
The formulations of the invention contain ionic zinc i.e. Zn2+ ions. The source of the ionic zinc will typically be a water-soluble zinc salt such as ZnCl2, ZnO, ZnSO4,
Zn(NO3)2 or Zn(acetate)2 and most suitably ZnCl2 or ZnO.
The concentration of the ionic zinc in the formulation will typically be more than 0.05% e.g. more than 0.1% e.g. more than 0.2%, more than 0.3% or more than 0.4% by weight of zinc based on the weight of insulin compound in the formulation. Thus, the concentration of the ionic zinc in the formulation may be more than 0.5% by weight of zinc based on the weight of insulin compound in the formulation, for example 0.5-1%, e.g. 0.5-0.75%, e.g. 0.5-0.6% by weight of zinc based on the weight of insulin compound in the formulation. For the purpose of the calculation the weight of the counter ion to zinc is excluded. The concentration of the ionic zinc in the formulation will (for example, for a formulation containing 100 U/ml of insulin compound) typically be more than 0.015 mM e.g. more than 0.03 mM e.g. more than 0.06 mM, more than 0.09 mM or more than 0.12 mM. Thus, the concentration of the ionic zinc in the formulation may be more than 0.15 mM, for example 0.15-0.60 mM, e.g. 0.20-0.45 mM, e.g. 0.25-0.35 mM.
In a formulation e.g. containing 1000 U/ml of insulin compound the concentration of the ionic zinc will typically be more than 0.15 mM e.g. more than 0.3 mM, e.g. more than 0.6 mM, more than 0.9 mM or more than 1.2 mM. Thus, the concentration of the ionic zinc in the formulation may be more than 1.5 mM, for example 1.5-6.0 mM, e.g. 2.0-4.5 mM, e.g. 2.5-3.5 mM.
The formulations of the invention contain a zinc binding species. Zinc binding species should be capable of complexing ionic zinc and will have a logK metal binding stability constant with respect to zinc ion binding of 4.5-12.3 as determined at 25 °C. Metal binding stability constants listed in the National Institute of Standards and Technology reference database 46 (Critically Selected Stability Constants of Metal Complexes) can be used. The database typically lists logK constants determined at 25 °C.

Therefore, the suitability of a zinc binding species for the present invention can be determined based on its logK metal binding stability constant with respect to zinc binding, as measured at 25 °C and as quoted by the database. The zinc binding species may also be described as an “accelerator” in the formulations according to the invention. Exemplary zinc binding species include polydendate organic anions. Thus, a preferred zinc binding species is citrate (logK = 4.93) which can, for example, be employed as trisodium citrate. Further examples include pyrophosphate (logK = 8.71), aspartate (logK = 5.87), glutamate (logK = 4.62), cysteine (logK = 9.11), cystine (logK = 6.67) and glutathione (logK = 7.98). Other possible zinc binding species include substances that can contribute a lone pair of electrons or electron density for interaction with ionic zinc such as polydendate amines including ethylenediamine (logK = 5.69), diethylenetriamine (DETA, logK = 8.88) and triethylenetetramine (TETA, logK = 11.95); and aromatic or heteroaromatic substances that can contribute a lone pair of electrons especially those comprising an imidazole moiety such as histidine (logK = 6.51). Thus, in one embodiment, the zinc binding species having a logK with respect to zinc ion binding in the range 4.5-12.3 is selected from citrate, pyrophosphate, aspartate, glutamate, cysteine, cystine, glutathione, ethylenediamine, histidine, DETA and TETA.
In an embodiment, the zinc binding species will have a logK metal binding stability constant with respect to zinc ion binding of 4.5-10 at 25 oC.
The most suitable concentration of the zinc binding species will depend on the agent and its logK value and will typically be in the range 1-100 mM e.g. 1-50 mM, 5-50 mM, 10-50 mM, 20-50 mM, 30-50 mM, 40-50 mM, 15-60 mM, 30-60 mM, 20-30 mM or 10-30 mM, in particular 15-60 mM e.g. 20-50 mM. The concentration of zinc binding species can be adjusted according to the particular concentration of insulin compound present in the composition in order to provide the desired accelerating effect. In a particular embodiment, the the zinc binding species is citrate. In a further embodiment, the concentrate of the citrate is 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM.
For example, the concentration of the zinc binding species in the formulation may typically be in the range 1-50 mM, more preferably 5-50 mM e.g. 10-50 mM e.g. 10-30 mM, more preferably around 20 mM (e.g. 22 mM), especially when the zinc binding species is citrate or histidine and especially for insulin compound 100 U/ml formulations.

Suitably the concentration of the zinc binding species in the formulation is 10-50 mM e.g. 30-50 mM e.g. 40-50 mM, more preferably around 44 mM when the zinc binding species is citrate or histidine for insulin compound 1000 U/ml formulations.
In an embodiment, the concentration of the zinc binding species is 10 mM or more. In a further embodiment, the zinc binding species is citrate and the concentration of the citrate is 10 mM or more e.g. 1-100 mM, 15-60 mM, 20-50 mM, 20-30 mM, or 30-60 mM.
Anionic zinc binding species may be employed as the free acid or a salt form, such as a salt form with sodium or calcium ions, especially sodium ions.
A mixture of zinc binding species may be employed, although a single zinc binding species is preferred.
Suitably the molar ratio of ionic zinc to zinc binding species in the formulation is in the range 1:1 to 1:1000 e.g.1:1 to 1:500 e.g. 1:1 to 1:250 or 1:3 to 1:500 e.g.1:3 to 1:175.
For example, a suitable molar ratio of ionic zinc to zinc binding species is 1:10-1:500 e.g. 1:20-1:500 e.g. 1:20-1:100 or 1:40-1:250, e.g. 1:40-1:90 or 1:60-1:200, e.g. 1:60-1:80, especially for citrate or histidine as zinc binding species. The following ranges are particularly of interest especially for citrate or histidine as zinc binding species: 1:10-1:500 e.g. 1:10-1:200 e.g. 1:10 to 1:100 e.g. 1:10-1:50, e.g. 1:10 to 1:30, e.g. 1:10- to 1:20 (especially for insulin compound 1000 U/ml formulation) or 1:50-1:100, e.g. 1:60-1:80 (especially for insulin compound 100 U/ml formulation).
For example, a formulation containing 100 U/ml of insulin compound may contain around 0.3 mM of ionic zinc (i.e. around 19.7 µg/ml of ionic zinc, i.e. around 0.54% by weight of zinc based on the weight of insulin compound in the formulation) and around 15-30 mM e.g. 20-30 mM zinc binding species (especially citrate).
For example, a formulation containing 1000 U/ml of insulin compound may contain around 3 mM of ionic zinc (i.e. around 197 µg/ml of ionic zinc, i.e. around 0.54% by weight of zinc based on the weight of insulin compound in the formulation) and around 30-60 mM e.g. 40-60 mM zinc binding species (especially citrate).
In one embodiment, the ratio of insulin compound concentration (U/ml) to zinc binding species (mM) in the formulation is in the range 100:1 to 2:1 e.g. 50:1 to 2:1 e.g. 40:1 to 2:1.

The formulations of the invention are substantially free of zinc binding species which have a logK metal binding stability constant with respect to zinc binding of more than 12.3 as determined at 25 °C. Specifically, the formulations of the invention are substantially free of EDTA (logK = 14.5). Further examples of zinc binding species which have a logK metal binding stability constant with respect to zinc binding of more than 12.3 to be avoided include EGTA (logK = 12.6). In general formulations of the invention will be substantially free of tetradentate ligands or ligands of higher denticity. In an embodiment, the formulations of the invention are also substantially free of zinc binding species which have a logK metal binding stability constant with respect to zinc ion binding of 10-12.3 as determined at 25 °C. “Substantially free” means that the concentration of zinc binding species which have a logK metal binding stability constant with respect to zinc binding as specified (such as EDTA) is less than 0.1 mM, such as less than 0.05 mM, such as less than 0.04 mM or less than 0.01 mM.
Zinc ion binding species which have acid forms (e.g. citric acid) may be introduced into the aqueous formulations of the invention in the form of a salt of the acid, such as a sodium salt (e.g. trisodium citrate). Alternatively, they can be introduced in the form of the acid with subsequent adjustment of pH to the required level. Thus, in an embodiment, the source of the citrate as zinc ion binding species is citric acid.
In one embodiment is provided an aqueous liquid pharmaceutical formulation comprising (i) an insulin compound at a concentration of 50-500 U/ml (ii) ionic zinc, (iii) citrate as a zinc binding species at a concentration of 1 mM or more, and (iv) a non-ionic surfactant which is an alkylglycoside; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C. Suitably, the citrate is present in the formulation at a concentration of 10-30 mM.
In another embodiment is provided an aqueous liquid pharmaceutical formulation comprising (i) an insulin compound at a concentration of 400-1000 U/ml e.g. 500-1000 U/ml (ii) ionic zinc, (iii) citrate as a zinc binding species at a concentration of 1 mM or more, and (iv) a non-ionic surfactant which is an alkyl glycoside; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C. Suitably, the citrate is present in the formulation at a concentration of 30-50 mM.

The formulations of the invention contain a non-ionic surfactant which is an
alkyl glycoside, especially dodecyl maltoside. In another embodiment, the alkyl glycoside
is decyl glucopyranoside. Other alkyl glycosides include dodecyl glucoside, octyl
glucoside, octyl maltoside, decyl glucoside, decyl maltoside, tridecyl glucoside, tridecyl
maltoside, tetradecyl glucoside, tetradecyl maltoside, hexadecyl glucoside, hexadecyl
maltoside, sucrose monooctanoate, sucrose monodecanoate, sucrose
monododecanoate, sucrose monotridecanoate, sucrose monotetradecanoate and sucrose monohexadecanoate. The concentration of the non-ionic surfactant in the formulation will typically be in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In one embodiment, the non-ionic surfactant is present at a concentration of 10-400 µg/ml e.g. 20-400 µg/ml, 50-400 µg/ml, 10-300 µg/ml, 20-300 µg/ml, 50-300 µg/ml, 10-200 µg/ml, 20-200 µg/ml, 50-200 µg/ml, 10-100 µg/ml, 20-100 µg/ml or 50-100 µg/ml.
In one embodiment, the concentration of insulin compound is 10-250 U/ml and the non-ionic surfactant is present at a concentration of 50-100 µg/ml. In this embodiment, suitably the non-ionic surfactant is dodecyl maltoside.
In another embodiment, the concentration of insulin compound is 10-<400 U/ml e.g. 20-400 U/ml, 50-400 U/ml, 10-300 U/ml, 20-300 U/ml, 50-300 U/ml, 10-200 U/ml, 20-200 U/ml, 50-200 U/ml, 10-100 U/ml, 20-100 U/ml or 50-100 U/ml, and the non-ionic surfactant is present at a concentration of 50-200 µg/ml. In this embodiment, suitably the non-ionic surfactant is dodecyl maltoside.
In another embodiment, the concentration of insulin compound is 400-1000 U/ml e.g. 500-1000 U/ml and the non-ionic surfactant is present at a concentration of 50-200 µg/ml. In this embodiment, suitably the non-ionic surfactant is dodecyl maltoside.
Suitably the pH of the aqueous formulations of the invention is in the range 5.5-9.0 especially 6.5-8.0 e.g. 7.0-7.8. e.g. 7.0-7.5. In order to minimise injection pain, the pH is preferably close to physiological pH (around pH 7.4). Another pH of interest is 7.6-8.0 e.g. around 7.8. An additional pH of interest is 7.2-7.8, e.g. around 7.6.
Suitably, the composition of the invention comprises a buffer (e.g. one or more buffers) in order to stabilise the pH of the formulation, which can also be selected to enhance protein stability. In one embodiment, a buffer is selected to have a pKa close

to the pH of the composition; for example, histidine is suitably employed as a buffer when the pH of the composition is in the range 5.0-7.0. Such a buffer may be employed in a concentration of 0.5-20 mM e.g. 2-5 mM. If histidine is included in the formulation as a zinc binding species it will also have a buffering role at this pH. As another example, phosphate e.g. sodium phosphate is suitably employed as a buffer when the pH of the composition is in the range 6.1-8.1. Such a buffer may be employed in a concentration of 0.5-20 mM e.g. 2-5 mM, e.g. 2 mM. Alternatively, in another embodiment, the formulation of the invention is further stabilised as disclosed in WO2008/084237 (herein incorporated by reference in its entirety), which describes a formulation comprising a protein and one or more additives, characterised in that the system is substantially free of a conventional buffer, i.e. a compound with an ionisable group having a pKa within 1 unit of the pH of the formulation at the intended temperature range of storage of the composition, such as 25 °C. In this embodiment, the pH of the formulation is set to a value at which the formulation has maximum measurable stability with respect to pH; the one or more additives (displaced buffers) are capable of exchanging protons with the insulin compound and have pKa values at least 1 unit more or less than the pH of the formulation at the intended temperature range of storage of the formulation. The additives may have ionisable groups having pKa between 1 to 5 pH units, preferably between 1 to 3 pH units, most preferably from 1.5 to 2.5 pH units, of the pH of the aqueous formulation at the intended temperature range of storage of the composition (e.g. 25 °C). Such additives may typically be employed at a concentration of 0.5-10 mM e.g. 2-5 mM.
The aqueous formulations of the present invention cover a wide range of osmolarity, including hypotonic, isotonic and hypertonic compositions. Preferably, the formulations of the invention are substantially isotonic. Suitably the osmolarity of the formulation is selected to minimize pain according to the route of administration e.g. upon injection. Preferred formulations have an osmolarity in the range of about 200 to about 500 mOsm/L. Preferably, the osmolarity is in the range of about 250 to about 350 mOsm/L. More preferably, the osmolarity is about 300 mOsm/L.
Tonicity of the formulation may be adjusted with a tonicity modifying agent (e.g. one or more tonicity modifying agents). Tonicity modifying agents may be charged or uncharged. Examples of charged tonicity modifying agents include salts such as a

combination of sodium, potassium, magnesium or calcium ions, with chloride, sulfate, carbonate, sulfite, nitrate, lactate, succinate, acetate or maleate ions (especially sodium chloride or sodium sulphate, particularly sodium chloride). The insulin compound formulations of the invention may contain a residual NaCl concentration of 2-4 mM as a result of the use of standard acidification and subsequent neutralization steps employed in preparing insulin formulations. Amino acids such as arginine, glycine or histidine may also be used for this purpose. Charged tonicity modifying agent (e.g. NaCl) is preferably used at a concentration of 100–300 mM, e.g. around 150 mM. In one embodiment, the formulation of the invention comprises >60 mM chloride e.g. sodium chloride, for example >65 mM, >75 mM, >80 mM, >90 mM, >100 mM, >120 mM or >140 mM, such as >60-300 mM, >60-200 mM, 50-175 mM, 75-300 mM, 75-200 mM or 75-175 mM. In one embodiment, the charged tonicity modifying agent in the formulation is sodium chloride at a concentration of 100–300 mM, e.g. around 150 mM.
In one embodiment, the insulin compound is insulin lispro at a concentration of 50-500 U/ml e.g. 50-200 U/ml such as 100 U/ml, and the charged tonicity modifying agent in the formulation is sodium chloride at a concentration of 100–300 mM, e.g. around 150 mM.
In one embodiment, the insulin compound is insulin aspart at a concentration of 50-500 U/ml e.g. 50-200 U/ml such as 100 U/ml, and the charged tonicity modifying agent in the formulation is sodium chloride at a concentration of 100–300 mM, e.g. around 150 mM.
In one embodiment, the insulin compound is insulin glulisine at a concentration of 50-500 U/ml e.g. 50-200 U/ml such as 100 U/ml, and the charged tonicity modifying agent in the formulation is sodium chloride at a concentration of 100–300 mM, e.g. around 150 mM.
Examples of uncharged tonicity modifying agents include sugars, sugar alcohols and other polyols, such as trehalose, sucrose, mannitol, glycerol, 1,2-propanediol, raffinose, lactose, dextrose, sorbitol or lactitol (especially trehalose, mannitol, glycerol or 1,2-propanediol, particularly glycerol). Uncharged tonicity modifying agent is preferably used at a concentration of 200–500 mM, e.g. around 300 mM. Another range of interest is 100-500 mM. In one embodiment, the uncharged tonicity modifying agent is used at a concentration of 100–300 mM, e.g. 150–200 mM, 170-180 mM or around

174 mM. In one embodiment, the uncharged tonicity modifying agent is glycerol at a concentration of 100–300 mM, e.g. 150-200 mM, 170-180 mM or around 174 mM.
When the insulin compound is insulin lispro, in particular at a concentration of >400 U/ml e.g. >400-1000 U/ml such as >500 U/ml e.g. >500-1000 U/ml or 1000 U/ml, the tonicity is suitably adjusted using an uncharged tonicity modifying agent, preferably at a concentration of 200–500 mM, e.g. around 300 mM. In this embodiment, the uncharged tonicity modifying agent is suitably selected from the group consisting of trehalose, mannitol, glycerol and 1,2-propanediol (most suitably glycerol). In another embodiment, the uncharged tonicity modifying agent is used at a concentration of 100– 300 mM, e.g. 150–200 mM, 170-180 mM or around 174 mM. In one embodiment, the uncharged tonicity modifying agent is glycerol at a concentration of 100–300 mM, e.g. 150-200 mM, 170-180 mM or around 174 mM.
When the insulin compound is insulin aspart at a concentration of >400 U/ml; such as > 500 U/ml (e.g. 1000 U/ml), the tonicity is suitably adjusted using an uncharged tonicity modifying agent, preferably at a concentration of 200–500 mM, e.g. around 300 mM. In this embodiment, the uncharged tonicity modifying agent is suitably selected from the group consisting of trehalose, mannitol, glycerol and 1,2-propanediol (most suitably glycerol). In another embodiment, the uncharged tonicity modifying agent is used at a concentration of 100–300 mM, e.g. 150–200 mM, 170-180 mM or around 174 mM. In one embodiment, the uncharged tonicity modifying agent is glycerol at a concentration of 100–300 mM, e.g. 150-200 mM, 170-180 mM or around 174 mM.
The ionic strength of a formulation may be calculated according to the
formula Ia:
in which cx is molar concentration of ion x (mol L-1), zx is the absolute value of the charge of ion x and the sum covers all ions (n) present in the composition. The contribution of the insulin compound itself should be ignored for the purposes of the calculation. The contribution of the zinc binding species should be ignored for the purposes of the calculation. Suitably, the contribution of the ionic zinc should be included for the purposes of the calculation. For zwitterions, the absolute value of the charge is the total charge excluding polarity, e.g. for glycine the possible ions have absolute charge of 0, 1 or 2 and for aspartate the possible ions have absolute charge of 0, 1, 2 or 3.

In general, the ionic strength of the formulation is suitably in the range of around 1 mM up to around 500 mM.
In one embodiment, the insulin compound is present at a concentration >400 U/ml or >500 U/ml e.g. >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml, >900-1000 U/ml or 1000 U/ml, and the ionic strength taking account of ions in the formulation except for the zinc binding species and the insulin compound is less than 40 mM, e.g. less than 30 mM, e.g. less than 20 mM, e.g. less than 10 mM such as 1-10 mM. In a further embodiment, the ionic strength taking account of ions in the formulation except for the zinc binding species and the insulin compound is less than 35 mM, less than 30 mM, less than 25 mM, less than 20 mM, less than 15 mM, or less than 10 mM, or is in the range 5-<40 mM, 5-30 mM, 5-20 mM, 2-20 mM, 1-10 mM, 2-10 mM or 5-10 mM. The tonicity may suitably be adjusted using an uncharged tonicity modifying agent.
When the insulin compound is insulin lispro, in particular insulin lispro at a concentration of >400 U/ml or >500 U/ml e.g. >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml, >900-1000 U/ml or 1000 U/ml, the ionic strength of the formulation is suitably kept to a minimum level since higher ionic strength formulations are less stable than lower ionic strength formulations, particularly at high concentrations of insulin. Suitably the ionic strength taking account of ions in the formulation except for the zinc binding species and the insulin compound is less than 40 mM, e.g. less than 30 mM, e.g. less than 20 mM, e.g. less than 10 mM such as 1-10 mM. In particular, the ionic strength taking account of ions in the formulation except for the zinc binding species and the insulin compound is less than 35 mM, less than 30 mM, less than 25 mM, less than 20 mM, less than 15 mM, or less than 10 mM, or is in the range 5-<40 mM, 5-30 mM, 5-20 mM, 2-20 mM, 1-10 mM, 2-10 mM or 5-10 mM. The tonicity may suitably be adjusted using an uncharged tonicity modifying agent.
When the insulin compound is insulin aspart at a concentration of >400 U/ml or >500 U/ml (e.g. >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml,

800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml, >900-1000 U/ml or 1000 U/ml), the ionic strength of the formulation is suitably kept to a minimum level since higher ionic strength formulations are less stable than lower ionic strength formulations. Suitably the ionic strength taking account of ions in the formulation except for the zinc binding species and the insulin compound is less than 40 mM, e.g. less than 30 mM, e.g. less than 20 mM, e.g. less than 10 mM. In particular, the ionic strength taking account of ions in the formulation except for the zinc binding species and the insulin compound is less than 35 mM, less than 30 mM, less than 25 mM, less than 20 mM, less than 15 mM, or less than 10 mM, or is in the range 5-<40 mM, 5-30 mM, 5-20 mM, 2-20 mM, 1-10 mM, 2-10 mM or 5-10 mM. The tonicity may suitably be adjusted using an uncharged tonicity modifying agent.
When the insulin compound is insulin glulisine at a concentration of >400 U/ml or > 500 U/ml (e.g. >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml, >900-1000 U/ml or 1000 U/ml), the ionic strength of the formulation is suitably kept to a minimum level since higher ionic strength formulations may be less stable than lower ionic strength formulations. Suitably the ionic strength taking account of ions in the formulation except for the zinc binding species and the insulin compound is less than 40 mM, e.g. less than 30 mM, e.g. less than 20 mM, e.g. less than 10 mM. In particular, the ionic strength taking account of ions in the formulation except for the zinc binding species and the insulin compound is less than 35 mM, less than 30 mM, less than 25 mM, less than 20 mM, less than 15 mM, or less than 10 mM, or is in the range 5-<40 mM, 5-30 mM, 5-20 mM, 2-20 mM, 1-10 mM, 2-10 mM or 5-10 mM. The tonicity may suitably be adjusted using an uncharged tonicity modifying agent.
In another embodiment, the ionic strength of a formulation may be calculated
according to the formula Ib:
in which cx is molar concentration of ion x (mol L-1), zx is the absolute value of the charge of ion x and the sum covers all ions (n) present in the composition, wherein the contribution of the insulin compound, zinc binding species and ionic zinc should be ignored for the purposes of the calculation. For zwitterions, the absolute value of the

charge is the total charge excluding polarity, e.g. for glycine the possible ions have absolute charge of 0, 1 or 2 and for aspartate the possible ions have absolute charge of 0, 1, 2 or 3.
In this embodiment, the ionic strength of the formulation is suitably in the range of around 1 mM up to around 500 mM.
In one embodiment, the insulin compound is present at a concentration >400 U/ml or >500 U/ml e.g. >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml, >900-1000 U/ml or 1000 U/ml, and the ionic strength taking account of ions in the formulation except for the zinc binding species, the insulin compound and the ionic zinc is less than 30 mM, e.g. less than 20 mM, e.g. less than 10 mM such as 1-10 mM. In a further embodiment, the ionic strength taking account of ions in the formulation except for the zinc binding species, the insulin compound and the ionic zinc is less than 25 mM, less than 20 mM, less than 15 mM, or less than 10 mM, or is in the range 5-<30 mM, 5-30 mM, 5-20 mM, 2-20 mM, 1-10 mM, 2-10 mM or 5-10 mM. The tonicity may suitably be adjusted using an uncharged tonicity modifying agent.
When the insulin compound is insulin lispro, in particular insulin lispro at a concentration of >400 U/ml or >500 U/ml e.g. >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml, >900-1000 U/ml or 1000 U/ml, the ionic strength of the formulation is suitably kept to a minimum level since higher ionic strength formulations are less stable than lower ionic strength formulations, particularly at high concentrations of insulin. Suitably the ionic strength taking account of ions in the formulation except for the zinc binding species, the insulin compound and the ionic zinc is less than 30 mM, e.g. less than 20 mM, e.g. less than 10 mM such as 1-10 mM. In particular, the ionic strength taking account of ions in the formulation except for the zinc binding species, the insulin compound and the ionic zinc is less than 25 mM, less than 20 mM, less than 15 mM, or less than 10 mM, or is in the range 5-<30 mM, 5-30 mM, 5-20 mM, 2-20 mM, 1-10 mM, 2-10 mM or 5-10 mM. The tonicity may suitably be adjusted using an uncharged tonicity modifying agent.

Alternatively, when the insulin compound is insulin aspart at a concentration of >400 U/ml or >500 U/ml (e.g. >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml, >900-1000 U/ml or 1000 U/ml), the ionic strength of the formulation is suitably kept to a minimum level since higher ionic strength formulations are less stable than lower ionic strength formulations. Suitably the ionic strength taking account of ions in the formulation except for the zinc binding species, the insulin compound and the ionic zinc is less than 30 mM, e.g. less than 20 mM, e.g. less than 10 mM. In particular, the ionic strength taking account of ions in the formulation except for the zinc binding species, the insulin compound and the ionic zinc is less than 25 mM, less than 20 mM, less than 15 mM, or less than 10 mM, or is in the range 5-<30 mM, 5-30 mM, 5-20 mM, 2-20 mM, 1-10 mM, 2-10 mM or 5-10 mM. The tonicity may suitably be adjusted using an uncharged tonicity modifying agent.
Alternatively, when the insulin compound is insulin glulisine at a concentration of >400 U/ml or >500 U/ml (e.g. >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml, >900-1000 U/ml or 1000 U/ml), the ionic strength of the formulation is suitably kept to a minimum level since higher ionic strength formulations may be less stable than lower ionic strength formulations. Suitably the ionic strength taking account of ions in the formulation except for the zinc binding species, the insulin compound and the ionic zinc is less than 30 mM, e.g. less than 20 mM, e.g. less than 10 mM. In particular, the ionic strength taking account of ions in the formulation except for the zinc binding species, the insulin compound and ionic zinc is less than 25 mM, less than 20 mM, less than 15 mM, or less than 10 mM, or is in the range 5-<30 mM, 5-30 mM, 5-20 mM, 2-20 mM, 1-10 mM, 2-10 mM or 5-10 mM. The tonicity may suitably be adjusted using an uncharged tonicity modifying agent.
The formulations of the invention can optionally include a preservative (e.g. one or more preservatives), preferably phenol, m-cresol, chlorocresol, benzyl alcohol, propylparaben, methylparaben, benzalkonium chloride or benzethonium chloride. In one embodiment, the formulation includes phenol or m-cresol. In one embodiment, a mixture of preservatives is employed e.g. phenol and m-cresol.

The formulations of the invention may optionally comprise nicotinamide. The presence of nicotinamide may further increase the speed of onset of action of insulin formulated in compositions of the invention. Suitably, the concentration of nicotinamide is in the range 10-150 mM, preferably in the range 20-100 mM, such as around 80 mM.
The formulations of the invention may optionally comprise nicotinic acid or a salt thereof. The presence of nicotinic acid or a salt thereof may also further increase the speed of onset of action of insulin formulated in compositions of the invention. Suitably, the concentration of nicotinic acid or a salt thereof is in the range 10-150 mM, preferably in the range 20-100 mM, such as around 80 mM. Example salts include metal salts such as sodium, potassium and magnesium salts.
Typically, one of nicotinamide and nicotinic acid (or as salt thereof) may be included in the formulation but not both.
The formulations of the invention may optionally comprise treprostinil or a salt thereof. The presence of the treprostinil may further increase the speed of onset of action of insulin formulated in compositions of the invention. Suitably, the concentration of treprostinil in the formulation is in the range of 0.1-12 µg/ml e.g. 0.1-10 µg/ml, 0.1-9 µg/ml, 0.1-8 µg/ml, 0.1-7 µg/ml, 0.1-6 µg/ml, 0.1-5 µg/ml, 0.1-4 µg/ml, 0.1-3 µg/ml, 0.1-2 µg/ml, 0.5-2 µg/ml e.g. about 1 µg/ml.
In one embodiment, the formulation does not contain a vasodilator. In a further embodiment, the formulation does not contain treprostinil, nicotinamide, nicotinic acid or a salt thereof.
Formulations of the invention may optionally include other beneficial components including stabilising agents. For example, amino acids such as arginine or proline may be included which may have stabilising properties. Thus, in one embodiment, the formulations of the invention comprise arginine.
In an embodiment of the invention the formulations are free of acids selected from glutamic acid, ascorbic acid, succinic acid, aspartic acid, maleic acid, fumaric acid, adipic acid and acetic acid and are also free from the corresponding ionic forms of these acids.
In an embodiment of the invention the formulations are free of arginine.
In an embodiment of the invention the formulations are free of protamine and protamine salts.

In an embodiment of the invention the formulations are free of magnesium ions.
The addition of magnesium ions e.g. in the form of magnesium chloride can provide a stabilising effect. Thus, in an embodiment of the invention a formulation contains magnesium ions e.g. MgCl2.
In an embodiment of the invention the formulations are free of calcium ions.
Formulations of the invention may further comprise an additional therapeutically active agent (an “active agent”), in particular an agent of use in the treatment of diabetes (i.e. in addition to the insulin compound in particular the rapid-acting insulin compound) e.g. an amylin analogue or a GLP-1 agonist. In one embodiment, the formulation further comprises an amylin analogue such as pramlintide, suitably at a concentration of 0.1-10 mg/ml e.g. 0.2-6 mg/ml. In one embodiment, the formulation further comprises a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide, suitably at a concentration of 10 µg/ml to 50 mg/ml e.g. 200 µg/ml to 10 mg/ml or 1-10 mg/ml.
Suitably the formulations of the invention are sufficiently stable that the concentration of high molecular weight species remains low upon extended storage. The term “high molecular weight species” as used herein, refers to any irreversibly formed component of the protein content which has an apparent molecular weight at least about double the molecular weight of the parent insulin compound, as detected by a suitable analytical method, such as size-exclusion chromatography. That is, high molecular weight species are multimeric aggregates of the parent insulin compound. The multimeric aggregates may comprise the parent protein molecules with considerably altered conformation or they may be an assembly of the parent protein units in the native or near-native conformation. The determination of high molecular weight species can be done using methods known in the art, including size exclusion chromatography, electrophoresis, analytical ultracentrifugation, light scattering, dynamic light scattering, static light scattering and field flow fractionation.
Suitably the formulations of the invention are sufficiently stable that they remain substantially free of visible particles after storage at 30°C for at least one, two or three months. Visible particles are suitably detected using the 2.9.20. European Pharmacopoeia Monograph (Particulate Contamination: Visible Particles). For example,

a formulation is substantially free of visible particles if it has a Visual score according to Visual Assessment Method B of 1, 2 or 3, especially 1 or 2 according to the definition given in the Examples section.
Suitably the formulations of the invention are sufficiently stable that the concentration of related species remains low upon extended storage. The term “related species” as used herein, refers to any component of the protein content formed by a chemical modification of the parent insulin compound, particularly desamido or cyclic imide forms of insulin. Related species are suitably detected by RP-HPLC.
In a preferred embodiment, the formulation of the invention retains at least 95%, e.g. at least 96%, e.g. at least 97%, e.g. at least 98%, e.g. at least 99% parent insulin compound (by weight of total protein) after storage at 30°C for one, two or three months. The percentage of insulin compound (by weight of total protein) may be determined by size-exclusion chromatography or RP-HPLC.
In a preferred embodiment, the formulation of the invention comprises no more than 4% (by weight of total protein), preferably no more than 2% high molecular weight species after storage at 30°C for one, two or three months.
In a preferred embodiment, the formulation of the invention comprises no more than 4% (by weight of total protein), preferably no more than 2%, preferably no more than 1% A-21 desamido form of the insulin compound after storage at 30°C for one, two or three months.
In preferred embodiments, a composition of the present invention should exhibit an increase in high molecular weight species during storage which is at least 10% lower, preferably at least 25% lower, more preferably at least 50% lower, than a composition lacking the non-ionic surfactant but otherwise identical, following storage under the same conditions (e.g. 30°C) and length of time (e.g. one, two or three months).
In preferred embodiments, a composition of the present invention should exhibit an increase in related species during storage which is at least 10% lower, preferably at least 25% lower, more preferably at least 50% lower, than a composition lacking the non-ionic surfactant but otherwise identical, following storage under the same conditions (e.g. 30°C) and length of time (e.g. one, two or three months).

The speed of action of a formulation of the invention may be determined in the
Diabetic Pig Pharmacokinetic/Pharmacodynamic Model (see Examples, General
Methods (c)). In preferred embodiments, a composition of the present invention
exhibits a Tmax (i.e. time to peak insulin concentration) that is at least 20% shorter, for
example preferably at least 30% shorter than a composition lacking the zinc binding
species having a logK with respect to zinc ion binding in the range 4.5-12.3 (e.g. in the
range 4.5-10) at 25 °C but otherwise identical, using the model. In preferred
embodiments, a composition of the present invention exhibits an area under the curve on the pharmacodynamics profile within the first 45 minutes after injection that is at least 20% greater, preferably at least 30% greater than a composition lacking the zinc binding species having a logK with respect to zinc ion binding in the range 4.5-12.3 (e.g. in the range 4.5-10) at 25 °C but otherwise identical, using the model.
In one embodiment, the present invention provides a composition comprising (i) an insulin compound e.g. a concentration of 400-1000 U/ml or 500-1000 U/ml, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C e.g. citrate, and (iv) a non-ionic surfactant which is an alkyl glycoside e.g. dodecyl maltoside; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C, which exhibits a TMAX (i.e. time to peak insulin concentration) that is at least 20% shorter, preferably at least 30% shorter than a formulation lacking the zinc binding species and non-ionic surfactant which is an alkylglycoside, but otherwise identical, using the Diabetic Pig Pharmacokinetic/Pharmacodynamic Model (see Examples, General Methods (c)).
In one embodiment, the present invention provides a composition comprising (i) an insulin compound e.g. a concentration of 400 U/ml or <400 U/ml e.g. 10-400 U/ml, 10-300 U/ml, 10-200 U/ml, 10-100 U/ml or 100 U/ml (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C e.g. citrate, and (iv) a non-ionic surfactant which is an alkyl glycoside e.g. dodecyl maltoside; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C, which exhibits a TMAX

(i.e. time to peak insulin concentration) that is at least 20% shorter, preferably at least 30% shorter than a formulation lacking the zinc binding species and non-ionic surfactant which is an alkylglycoside, but otherwise identical, using the Diabetic Pig Pharmacokinetic/Pharmacodynamic Model (see Examples, General Methods (c)).
In one embodiment, the present invention provides a composition comprising (i)
insulin lispro e.g. a concentration of 400-1000 U/ml or 500-1000 U/ml, (ii) ionic zinc, (iii)
a zinc binding species at a concentration of 1 mM or more selected from species having
a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C e.g. citrate, and (iv)
a non-ionic surfactant which is an alkyl glycoside e.g. dodecyl maltoside; and wherein
the formulation is substantially free of EDTA and any other zinc binding species having a
logK with respect to zinc ion binding of more than 12.3 at 25 °C, which exhibits a TMAX
(i.e. time to peak insulin concentration) substantially the same as (e.g. within ±20% e.g.
±10%) that of an aqueous formulation consisting of: insulin lispro (100 U/ml), sodium
phosphate (13.2 mM), glycerol (174 mM), m-cresol (29 mM), ionic zinc (19.7 µg/ml,
excluding counter-ion) adjusted to pH 7.3, using the Diabetic Pig
Pharmacokinetic/Pharmacodynamic Model (see Examples, General Methods (c)).
In one embodiment, the present invention provides a composition comprising (i)
insulin lispro e.g. a concentration of 400-1000 U/ml or 500-1000 U/ml, (ii) ionic zinc, (iii)
a zinc binding species at a concentration of 1 mM or more selected from species having
a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C e.g. citrate, and (iv)
a non-ionic surfactant which is an alkyl glycoside e.g. dodecyl maltoside; and wherein
the formulation is substantially free of EDTA and any other zinc binding species having a
logK with respect to zinc ion binding of more than 12.3 at 25 °C, which exhibits a TMAX
(i.e. time to peak insulin concentration) that is at least 20% shorter, preferably at least
30% shorter than an aqueous formulation consisting of: insulin lispro (100 U/ml), sodium
phosphate (13.2 mM), glycerol (174 mM), m-cresol (29 mM), ionic zinc (19.7 µg/ml,
excluding counter-ion) adjusted to pH 7.3, using the Diabetic Pig
Pharmacokinetic/Pharmacodynamic Model (see Examples, General Methods (c)).
In another embodiment, the present invention provides a composition comprising (i) an insulin compound e.g. at a concentration of 400-1000 U/ml or 500-1000 U/ml, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3

at 25 °C e.g. citrate, and (iv) a non-ionic surfactant which is an alkyl glycoside e.g. dodecyl maltoside; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C, which exhibits an area under the curve on the pharmacodynamics profile within the first 45 minutes after injection that is at least 20% greater, preferably at least 30% greater than that of a formulation lacking the zinc binding species and non-ionic surfactant which is an alkylglycoside, but otherwise identical, using the Diabetic Pig Pharmacokinetic/Pharmacodynamic Model (see Examples, General Methods (c)).
In another embodiment, the present invention provides a composition
comprising (i) an insulin compound e.g. a concentration of 400 U/ml or <400 U/ml e.g.
10-400 U/ml, 10-300 U/ml, 10-200 U/ml, 10-100 U/ml or 100 U/ml, (ii) ionic zinc, (iii) a
zinc binding species at a concentration of 1 mM or more selected from species having a
logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C e.g. citrate, and (iv) a
non-ionic surfactant which is an alkyl glycoside e.g. dodecyl maltoside; and wherein the
formulation is substantially free of EDTA and any other zinc binding species having a
logK with respect to zinc ion binding of more than 12.3 at 25 °C, which exhibits an area
under the curve on the pharmacodynamics profile within the first 45 minutes after
injection that is at least 20% greater, preferably at least 30% greater than that of a
formulation lacking the zinc binding species and non-ionic surfactant which is an
alkylglycoside, but otherwise identical, using the Diabetic Pig
Pharmacokinetic/Pharmacodynamic Model (see Examples, General Methods (c)).
In another embodiment, the present invention provides a composition comprising (i) insulin lispro e.g. at a concentration of 400-1000 U/ml or 500-1000 U/ml, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C e.g. citrate, and (iv) a non-ionic surfactant which is an alkyl glycoside e.g. dodecyl maltoside; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C, which exhibits an area under the curve on the pharmacodynamics profile within the first 45 minutes after injection that is substantially the same as (e.g. within ±20% e.g. ±10%) that of am aqueous formulation consisting of: insulin lispro (100 U/ml), sodium phosphate (13.2 mM), glycerol (174 mM), m-cresol (29 mM), ionic zinc (19.7 µg/ml,

excluding counter-ion) adjusted to pH 7.3, using the Diabetic Pig
Pharmacokinetic/Pharmacodynamic Model (see Examples, General Methods (c)).
In another embodiment, the present invention provides a composition
comprising (i) insulin lispro e.g. at a concentration of 400-1000 U/ml or 500-1000 U/ml,
(ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected
from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C
e.g. citrate, and (iv) a non-ionic surfactant which is an alkyl glycoside e.g. dodecyl
maltoside; and wherein the formulation is substantially free of EDTA and any other zinc
binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C,
which exhibits an area under the curve on the pharmacodynamics profile within the first
45 minutes after injection that is at least 20% greater, preferably at least 30% greater
than an aqueous formulation consisting of: insulin lispro (100 U/ml), sodium phosphate
(13.2 mM), glycerol (174 mM), m-cresol (29 mM), ionic zinc (19.7 µg/ml, excluding
counter-ion) adjusted to pH 7.3, using the Diabetic Pig
Pharmacokinetic/Pharmacodynamic Model (see Examples, General Methods (c)).
In one embodiment, the present invention provides a composition comprising (i) insulin aspart e.g. at a concentration of 400-1000 U/ml or 500-1000 U/ml, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C e.g. citrate, and (iv) a non-ionic surfactant which is an alkyl glycoside e.g. dodecyl maltoside; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C which exhibits a Tmax (i.e. time to peak insulin concentration) that is at least 20% shorter, preferably at least 30% shorter than an aqueous formulation consisting of: insulin aspart (100 U/ml), sodium phosphate (7 mM), glycerol (174 mM), sodium chloride (10 mM), phenol (15.9 mM), m-cresol (15.9 mM) and ionic zinc (19.7 µg/ml, excluding counter-anion) adjusted to pH 7.4, using the Diabetic Pig Pharmacokinetic/Pharmacodynamic Model (see Examples, General Methods (c)).
In one embodiment, the present invention provides a composition comprising (i) insulin aspart e.g. at a concentration of 400-1000 U/ml or 500-1000 U/ml, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C e.g. citrate,

and (iv) a non-ionic surfactant which is an alkyl glycoside e.g. dodecyl maltoside; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C which exhibits a Tmax (i.e. time to peak insulin concentration) that is substantially the same as (e.g. within ±20% e.g. ±10%) that of an aqueous formulation consisting of: insulin aspart (100 U/ml), sodium phosphate (7 mM), glycerol (174 mM), sodium chloride (10 mM), phenol (15.9 mM), m-cresol (15.9 mM) and ionic zinc (19.7 µg/ml, excluding counter-anion) adjusted to pH 7.4, using the Diabetic Pig Pharmacokinetic/Pharmacodynamic Model (see Examples, General Methods (c)).
In another embodiment, the present invention provides a composition comprising (i) insulin aspart e.g. at a concentration of 400-1000 U/ml or 500-1000 U/ml, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C e.g. citrate, and (iv) a non-ionic surfactant which is an alkyl glycoside e.g. dodecyl maltoside; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C, which exhibits an area under the curve on the pharmacodynamics profile within the first 45 minutes after injection that is at least 20% greater, preferably at least 30% greater than an aqueous formulation consisting of: insulin aspart (100 U/ml), sodium phosphate (7 mM), glycerol (174 mM), sodium chloride (10 mM), phenol (15.9 mM), m-cresol (15.9 mM) and ionic zinc (19.7 µg/ml, excluding counter-anion) adjusted to pH 7.4, using the Diabetic Pig Pharmacokinetic/Pharmacodynamic Model (see Examples, General Methods (c)).
In another embodiment, the present invention provides a composition comprising (i) insulin aspart e.g. at a concentration of 400-1000 U/ml or 500-1000 U/ml, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C e.g. citrate, and (iv) a non-ionic surfactant which is an alkyl glycoside e.g. dodecyl maltoside; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C, which exhibits an area under the curve on the pharmacodynamics profile within the first 45 minutes after injection that is substantially the same as (e.g. within ±20% e.g. ±10%)

that of an aqueous formulation consisting of: insulin aspart (100 U/ml), sodium phosphate (7 mM), glycerol (174 mM), sodium chloride (10 mM), phenol (15.9 mM), m-cresol (15.9 mM) and ionic zinc (19.7 µg/ml, excluding counter-anion) adjusted to pH 7.4, using the Diabetic Pig Pharmacokinetic/Pharmacodynamic Model (see Examples, General Methods (c)).
In another aspect of the invention is provided an aqueous liquid pharmaceutical formulation comprising (i) an insulin compound at a concentration of 400-1000 U/ml and (ii) ionic zinc; wherein the formulation is bioequivalent to a corresponding formulation comprising the insulin compound at a concentration of 100 U/ml.
As used herein, “bioequivalent” means that the formulation of the invention has
an equivalent or similar pharmacokinetic/pharmacodynamic (PK/PD) profile to a
corresponding formulation. For example, the formulation of the invention exhibits a
TMAX or T½MAX (measured in accordance with the diabetic pig
pharmacokinetic/pharmacodynamic model described in section (c) of General Methods)
which is substantially the same as (e.g. within ±20%, e.g. within ±10%) of that of the
corresponding formulation. Bioequivalence can also be established by applying the
Student’s t-test to the pharmacokinetic/pharmacodynamics results achieved using two
different compositions as described in the diabetic pig
pharmacokinetic/pharmacodynamic model described in section (c) of General Methods.
By “corresponding formulation” is meant a standard formulation e.g. a commercially available formulation of the same insulin compound at a concentration of 100 U/ml such as Humalog® (for insulin lispro) or NovoRapid® (for insulin aspart) or Apidra® (for insulin glulisine).
In one embodiment, the insulin compound is present at a concentration of 400-1000 U/ml e.g. >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml e.g. 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the insulin compound is present at a concentration of 1000 U/ml.
In one embodiment is provided an aqueous liquid pharmaceutical formulation comprising (i) insulin lispro at a concentration of 500-1000 U/ml and (ii) ionic zinc; wherein the formulation is bioequivalent to a commercial formulation of insulin lispro at a concentration of 100 U/ml e.g. an aqueous formulation consisting of: insulin lispro

(100 U/ml), sodium phosphate (13.2 mM), glycerol (174 mM), m-cresol (29 mM), ionic
zinc (19.7 µg/ml, excluding counter-ion) adjusted to pH 7.3 (i.e. the formulation of Humalog®).
In one embodiment is provided an aqueous liquid pharmaceutical formulation comprising (i) insulin aspart at a concentration of 500-1000 U/ml and (ii) ionic zinc; wherein the formulation is bioequivalent to a commercial formulation of insulin aspart at a concentration of 100 U/ml e.g. an aqueous formulation consisting of: insulin aspart (100 U/ml), sodium phosphate (7 mM), glycerol (174 mM), sodium chloride (10 mM), phenol (15.9 mM), m-cresol (15.9 mM) and ionic zinc (19.7 µg/ml, excluding counter-anion) adjusted to pH 7.4 (i.e. the formulation of NovoRapid®).
In one embodiment of the formulation, the total percentage increase in related species during storage (e.g. at 30 °C for 1, 2 or 3 months) is no higher than that of a corresponding formulation comprising the insulin compound at a concentration of 100 U/ml. In another embodiment, the formulation comprises a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C, which is suitably citrate. In one embodiment, the concentration of zinc binding species is from 30 mM to 50 mM. In one embodiment, the formulation comprises a non-ionic surfactant, especially a non-ionic surfactant such as an alkyl glycoside e.g. dodecyl maltoside. In one embodiment, the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C. In one embodiment, a Student’s t-test applied to the TMAX of the aqueous liquid pharmaceutical formulation comprising an insulin compound at a concentration of 500-1000 U/ml and the corresponding formulation comprising the same insulin compound at a concentration of 100 U/ml provides a p-value of ≥0.05. In one embodiment, the formulation does not contain a vasodilator. In a further embodiment, the formulation does not contain treprostinil, nicotinamide, nicotinic acid or a salt thereof.
According to further aspects of the invention, there is provided a formulation of the invention for use in the treatment of a subject suffering from diabetes mellitus. There is also provided a method of treatment of diabetes mellitus which comprises administering to a subject in need thereof an effective amount of a formulation of the invention.

A typical insulin compound dose of the composition of the invention is 2-30 U, e.g. 5-15 U. Administration should suitably occur in the window between 15 minutes before eating (i.e. before start of a meal) and 15 minutes after eating (i.e. after end of a meal).
In one embodiment, the formulation of the invention is co-administered with a long acting insulin such as insulin glargine or insulin degludec, suitably at a concentration of 50-1000 U/ml e.g. 100-500 U/ml or 100-200 U/ml.
In one embodiment, the composition of the invention is for administration by intravenous injection or infusion, or subcutaneous or intramuscular injection. In one embodiment, the composition of the invention is not for administration by intranasal delivery.
An aspect of the invention is a container e.g. made of plastics or glass containing one dose or a plurality of doses of the formulation of the invention. The container can, for example, be a cartridge designed to be a replaceable item for use with an injection device.
The formulations of the invention may suitably be packaged for injection,
especially sub-cutaneous or intramuscular injection. Sub-cutaneous injection is
preferred. Injection may be by conventional syringe or more preferably via a pen device adapted for use by diabetic subjects. Exemplary pen devices include the Kwikpen® device and the Flexpen® device.
An aspect of the invention is an injection device, particularly a device adapted for subcutaneous or intramuscular injection, for single or multiple use comprising a container containing one dose or a plurality of doses of the formulation of the invention together with an injection needle. In an embodiment, the container is a replaceable cartridge which contains a plurality of doses. In an embodiment, the needle is replaceable e.g. after each occasion of use.
Another aspect of the invention is a medical device comprising a reservoir comprising a plurality of doses of the formulation of the invention and a pump adapted for automatic or remote operation such that upon automatic or remote operation one or more doses of the formulation of the invention is administered to the body e.g. subcutaneously or intramuscularly. Such devices may be worn on the outside of the body or implanted in the body.

Formulations of the invention may be prepared by mixing the ingredients. For example, the insulin compound may be dissolved in an aqueous formulation comprising the other components. Alternatively, the insulin compound may be dissolved in a strong acid (typically HCl), after dissolution diluted with an aqueous formulation comprising the other components, and then pH adjusted to the desired pH with addition of alkali (e.g. NaOH). As a variation on this method, a step of neutralising the acid solution may be performed before the dilution step and it may then not be necessary to adjust the pH after the dilution step (or a small adjustment only may be necessary).
According to another aspect of the invention there is provided a dry solid
pharmaceutical composition suitable for reconstitution with an aqueous medium which
comprises, following reconstitution, (i) an insulin compound, (ii) ionic zinc e.g. at a
concentration of 0.05% or more e.g. 0.5% or more by weight of zinc based on the weight
of insulin compound in the formulation, (iii) a zinc binding species at a concentration of
1 mM or more selected from species having a logK with respect to zinc ion binding in the
range 4.5-12.3 at 25 °C, and (iv) a non-ionic surfactant which is an alkyl glycoside; and
wherein the composition is substantially free of EDTA and any other zinc binding species
having a logK with respect to zinc ion binding of more than 12.3 at 25 °C. Thus, a
formulation of the invention may be prepared by dissolving such a dry solid
pharmaceutical composition in an aqueous medium e.g. water or saline. Such a dry solid
pharmaceutical composition may be prepared by dehydrating (e.g. freeze drying) a
formulation of the invention. The invention also provides a container containing one
dose or a plurality of doses of such a dry solid pharmaceutical composition.
Further aspects of the invention include:
• A method of improving the storage stability of an aqueous liquid pharmaceutical
formulation comprising (i) an insulin compound, (ii) ionic zinc e.g. at a
concentration of 0.05% or more e.g. 0.5% or more by weight of zinc based on
the weight of insulin compound in the formulation and (iii) a zinc binding species
at a concentration of 1 mM or more selected from species having a logK with
respect to zinc ion binding in the range 4.5-12.3 at 25 °C e.g. citrate; wherein the
formulation is substantially free of EDTA and any other zinc binding species
having a logK with respect to zinc ion binding of more than 12.3 at 25 °C; which
comprises adding a non-ionic surfactant which is an alkyl glycoside, particularly

dodecyl maltoside, to the formulation. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate and the citrate concentration in the formulation is 1-100 mM, e.g. 15-60 mM, e.g. 20-50, 20-30 mM, e.g. 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • A method of improving the storage stability of an aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc e.g. at a concentration of 0.05% or more e.g. 0.5% or more by weight of zinc based on the weight of insulin compound in the formulation; (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C e.g. citrate; (iv) optionally one or more buffers e.g. phosphate such as sodium phosphate; (v) optionally one or more preservatives e.g. phenol and m-cresol; and (vi) optionally one or more tonicity modifiers e.g. glycerol or NaCl; wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C; which comprises adding a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside, to the formulation. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate and the citrate concentration in the formulation is 1-100 mM, e.g. 15-60 mM, e.g. 20-50, 20-30 mM, e.g. 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.

• A method of improving the storage stability of an aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc e.g. at a concentration of 0.05% or more e.g. 0.5% or more by weight of zinc based on the weight of insulin compound in the formulation; (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C e.g. citrate; (iv) optionally one or more buffers e.g. phosphate such as sodium phosphate; (v) optionally one or more preservatives e.g. phenol and m-cresol; and (vi) optionally one or more tonicity modifiers e.g. glycerol or NaCl; which comprises adding a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside, to the formulation. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate and the citrate concentration in the formulation is 1-100 mM, e.g. 15-60 mM, e.g. 20-50, 20-30 mM, e.g. 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• Use of a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside, to improve the storage stability of an aqueous liquid pharmaceutical formulation comprising (i) an insulin compound, (ii) ionic zinc e.g. at a concentration of 0.05% or more e.g. 0.5% or more by weight of zinc based on the weight of insulin compound in the formulation and (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C e.g. citrate; wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate and the citrate concentration in the formulation is1-100 mM, e.g. 15-60

mM, e.g. 20-50, 20-30 mM, e.g. 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• Use of a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside, to improve the storage stability of an aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc e.g. at a concentration of 0.05% or more e.g. 0.5% or more by weight of zinc based on the weight of insulin compound in the formulation; (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C e.g. citrate; (iv) optionally one or more buffers e.g. phosphate such as sodium phosphate; (v) optionally one or more preservatives e.g. phenol and m-cresol; and (vi) optionally one ore more tonicity modifiers e.g. glycerol or NaCl, wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate and the citrate concentration in the formulation is 1-100 mM, e.g. 15-60 mM, e.g. 20-50, 20-30 mM, e.g. 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• Use of a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside, to improve the storage stability of an aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc e.g. at a concentration of 0.05% or more e.g. 0.5% or more by weight of zinc based on the weight of insulin compound in the formulation; (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with

respect to zinc ion binding in the range 4.5-12.3 at 25 °C e.g. citrate; (iv) optionally one or more buffers e.g. phosphate such as sodium phosphate; (v) optionally one or more preservatives e.g. phenol and m-cresol; and (vi) optionally one ore more tonicity modifiers e.g. glycerol or NaCl. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate and the citrate concentration in the formulation is 1-100 mM, e.g. 15-60 mM, e.g. 20-50, 20-30 mM, e.g. 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• An aqueous liquid pharmaceutical formulation comprising (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate, and (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration is 1-100 mM, e.g. 15-60 mM, e.g. 20-50, 20-30 mM, e.g. 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate, (iv) a non-ionic surfactant which is an alkyl

glycoside, particularly dodecyl maltoside; (v) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vi) optionally one or more preservatives e.g. phenol and m-cresol; (vii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, and (viii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, e.g. 20-50, 20-30 mM, e.g. 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate, (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; (v) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vi) optionally one or more preservatives e.g. phenol and m-cresol; (vii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, and (viii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, e.g. 20-50, 20-30 mM, e.g. 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third

further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• An aqueous liquid pharmaceutical formulation comprising (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate, and (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, e.g. 20-50, 20-30 mM, e.g. 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate, and (iv) a non-ionic surfactant which is an

alkyl glycoside, particularly dodecyl maltoside; (v) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vi) optionally one or more preservatives e.g. phenol and m-cresol; (vii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, and (viii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, e.g. 20-50, 20-30 mM, e.g. 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; (v) optionally one or more buffers e.g.

phosphate such as sodium phosphate; (vi) optionally one or more preservatives e.g. phenol and m-cresol; (vii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, and (viii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide; wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, e.g. 20-50, 20-30 mM, e.g. 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation comprising (i) an insulin compound, (ii) ionic zinc, (iii) citrate as a zinc binding species at a concentration of 1 mM, and (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500

U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the citrate concentration is 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc, (iii) citrate as a zinc binding species at a concentration of 1 mM or more, (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; (v) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vi) optionally one or more preservatives e.g. phenol and m-cresol; (vii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, and (viii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide, and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-

<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the citrate concentration is 1-100 mM, e.g. 15-60 mM, e.g. 20-50, 20-30 mM, e.g. 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc, (iii) citrate as a zinc binding species at a concentration of 1 mM or more, (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; (v) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vi) optionally one or more preservatives e.g. phenol and m-cresol; (vii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, and (viii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000

U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the citrate concentration is 1-100 mM, e.g. 15-60 mM, e.g. 20-50, 20-30 mM, e.g. 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation comprising (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate, (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; and (v) treprostinil or a salt thereof; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the treprostinil is at a concentration in the range 0.1-12 µg/ml e.g. 0.1-10 µg/ml, 0.1-9 µg/ml, 0.1-8 µg/ml, 0.1-7 µg/ml, 0.1-6 µg/ml, 0.1-5 µg/ml, 0.1-4 µg/ml, 0.1-3 µg/ml, 0.1-2 µg/ml, 0.5-2 µg/ml e.g. about 1 µg/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially

around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C, (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; (v) treprostinil or a salt thereof; (vi) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vii) optionally one or more preservatives e.g. phenol and m-cresol; (viii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, and (viii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide, and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the treprostinil is at a concentration in the range 0.1-12 µg/ml e.g. 0.1-10 µg/ml, 0.1-9 µg/ml, 0.1-8 µg/ml, 0.1-7 µg/ml, 0.1-6 µg/ml, 0.1-5 µg/ml, 0.1-4 µg/ml, 0.1-3 µg/ml, 0.1-2 µg/ml, 0.5-2 µg/ml e.g. about 1 µg/ml. In one

embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C, (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; (v) treprostinil or a salt thereof; (vi) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vii) optionally one or more preservatives e.g. phenol and m-cresol; (viii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, and (viii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the treprostinil is at a concentration in the range 0.1-12 µg/ml e.g. 0.1-10 µg/ml, 0.1-9 µg/ml, 0.1-8 µg/ml, 0.1-7 µg/ml, 0.1-6 µg/ml, 0.1-5 µg/ml, 0.1-4 µg/ml, 0.1-3 µg/ml, 0.1-2 µg/ml, 0.5-2 µg/ml e.g. about 1 µg/ml. In one

embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation comprising (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate, (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; and (v) nicotinamide, nicotinic acid or a salt thereof; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the nicotinamide, nicotinic acid or salt thereof is at a concentration in the range 10-150 mM, e.g. 20-100 mM such as around 80 mM. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-

30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation comprising (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate, (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; and (v) an amylin analogue such as pramlintide; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the amylin analogue, e.g. pramlintide, is at a concentration in the range 0.1-10 mg/ml, e.g. 0.2-6 mg/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further

embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate, (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; (v) an amylin analogue such as pramlintide; (vi) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vii) optionally one or more preservatives e.g. phenol and m-cresol; and (viii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the amylin analogue, e.g. pramlintide is at a concentration in the range 0.1-10 mg/ml, e.g. 0.2-6 mg/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin

compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate, (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; (v) an amylin analogue such as pramlintide; (vi) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vii) optionally one or more preservatives e.g. phenol and m-cresol; and (viii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the amylin analogue, e.g. pramlintide is at a concentration in the range 0.1-10 mg/ml, e.g. 0.2-6 mg/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.

• An aqueous liquid pharmaceutical formulation comprising (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate, (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; and (v) a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the GLP-1 agonist, e.g. liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide is at a concentration range of 10 µg/ml to 50 mg/ml, 200 ug/ml to 10 mg/ml, or 1-10 mg/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM

or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C, (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; (v) a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide; (vi) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vii) optionally one or more preservatives e.g. phenol and m-cresol; and (viii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the GLP-1 agonist, e.g. liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide is at a concentration range of 10 µg/ml to 50 mg/ml, 200 ug/ml to 10 mg/ml, or 1-10 mg/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, e.g. 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is inslulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM

or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C, (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; (v) a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide; (vi) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vii) optionally one or more preservatives e.g. phenol and m-cresol; and (viii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the GLP-1 agonist, e.g. liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide is at a concentration range of 10 µg/ml to 50 mg/ml, 200 ug/ml to 10 mg/ml, or 1-10 mg/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, e.g. 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is inslulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C, (iv) a non-ionic surfactant which is an alkyl glycoside,

particularly dodecyl maltoside; (v) nicotinamide, nicotinic acid or a salt thereof; (vi) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vii) optionally one or more preservatives e.g. phenol and m-cresol; and (viii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the nicotinamide, nicotinic acid or salt thereof is at a concentration in the range of 10-150 mM, e.g. 20-100 mM such as around 80 mM. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C, (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; (v) nicotinamide, nicotinic acid or a salt thereof;

(vi) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vii) optionally one or more preservatives e.g. phenol and m-cresol; and (viii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, wherein the insulin compound is present at a concentration of 10-1000 U/ml, such as 50-500 U/ml, 50-200 U/ml, 100 U/ml, 1000 U/ml, 50-1000 U/ml, 10-500 U/ml, 10 to <500 U/ml, 50-500 U/ml, 50-<500 U/ml, 100-500 U/ml, 100-<500 U/ml, 10-400 U/ml, 10 to <400 U/ml, 50-400 U/ml, 50-<400 U/ml, 100-400 U/ml, 100-<400 U/ml, 10-300 U/ml, 10-<300 U/ml, 50-300 U/ml, 50-<300 U/ml, 100-300 U/ml, 100-<300 U/ml, 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml, 100-<200 U/ml, 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the nicotinamide, nicotinic acid or salt thereof is at a concentration in the range of 10-150 mM, e.g. 20-100 mM such as around 80 mM. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation comprising (i) an insulin compound at a concentration of 50-500 U/ml e.g. 50-200 U/ml e.g. around 100 U/ml, (ii) ionic zinc, (iii) citrate as a zinc binding species at a concentration of 1 mM or more (suitably 10-50 mM e.g. 10-30 mM e.g. around 20 mM such as 22 mM), and (iv) a non-ionic surfactant which is an alkyl glycoside such as dodecyl maltoside); and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C (for example is substantially free of EDTA and any other zinc

binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C). In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the citrate concentration is 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound at a concentration of 50-500 U/ml e.g. 50-200 U/ml e.g. around 100 U/ml, (ii) ionic zinc, (iii) citrate as a zinc binding species at a concentration of 1 mM or more (suitably 10-50 mM e.g. 10-30 mM e.g. around 20 mM such as 22 mM), (iv) a non-ionic surfactant which is an alkyl glycoside such as dodecyl maltoside; (v) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vi) optionally one or more preservatives e.g. phenol and m-cresol; (vii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, suitably NaCl e.g. at a concentration of 100-300 mM e.g. around 150 mM, and (viii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C (for example is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C). In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the citrate concentration is 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine.

In a fourth further embodiment, the insulin compound is recombinant human insulin.
• An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound at a concentration of 50-500 U/ml e.g. 50-200 U/ml e.g. around 100 U/ml, (ii) ionic zinc, (iii) citrate as a zinc binding species at a concentration of 1 mM or more (suitably 10-50 mM e.g. 10-30 mM e.g. around 20 mM such as 22 mM), (iv) a non-ionic surfactant which is an alkyl glycoside such as dodecyl maltoside; (v) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vi) optionally one or more preservatives e.g. phenol and m-cresol; (vii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, suitably NaCl e.g. at a concentration of 100-300 mM e.g. around 150 mM, and (viii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the citrate concentration is 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• An aqueous liquid pharmaceutical formulation comprising (i) an insulin compound at a concentration of 500-1000 U/ml e.g. 800-1000 U/ml e.g. around 1000 U/ml, (ii) ionic zinc, (iii) citrate as a zinc binding species at a concentration of 1 mM or more (suitably 30-50 mM e.g. 40-50 mM e.g. around 44 mM), and (iv) a non-ionic surfactant which is an alkyl glycoside such as dodecyl maltoside); and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C (for example is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C). In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration

in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the citrate concentration is 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound at a concentration of 500-1000 U/ml e.g. 800-1000 U/ml e.g. around 1000 U/ml, (ii) ionic zinc, (iii) citrate as a zinc binding species at a concentration of 1 mM or more (suitably 30-50 mM e.g. 40-50 mM e.g. around 44 mM), (iv) a non-ionic surfactant which is an alkyl glycoside such as dodecyl maltoside; (v) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vi) optionally one or more preservatives e.g. phenol and m-cresol; (vii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, suitably glycerol e.g. at a concentration of 100-300 mM e.g. 150-200 mM, 170-180 mM or 174 mM, and (viii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C (for example is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C). In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the citrate concentration is 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.

• An aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound at a concentration of 500-1000 U/ml e.g. 800-1000 U/ml e.g. around 1000 U/ml, (ii) ionic zinc, (iii) citrate as a zinc binding species at a concentration of 1 mM or more (suitably 30-50 mM e.g. 40-50 mM e.g. around 44 mM), (iv) a non-ionic surfactant which is an alkyl glycoside such as dodecyl maltoside; (v) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vi) optionally one or more preservatives e.g. phenol and m-cresol; (vii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, suitably glycerol e.g. at a concentration of 100-300 mM e.g. 150-200 mM, 170-180 mM or 174 mM, and (viii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the citrate concentration is 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• A dry solid pharmaceutical composition suitable for reconstitution with an aqueous medium which comprises, following reconstitution, (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate, and (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; and wherein the composition is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60

mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• A dry solid pharmaceutical composition suitable for reconstitution with an aqueous medium which consists of, following reconstitution, (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate, (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; (v) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vi) optionally one or more preservatives e.g. phenol and m-cresol; (vii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, and (viii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide; and wherein the composition is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• A dry solid pharmaceutical composition suitable for reconstitution with an aqueous medium which consists of, following reconstitution, (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate, (iv) a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside; (v) optionally one or more buffers e.g. phosphate such as sodium phosphate; (vi) optionally one or more preservatives

e.g. phenol and m-cresol; (vii) optionally one or more tonicity modifiers e.g. glycerol or NaCl, and (viii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• A method of improving the storage stability of an aqueous liquid pharmaceutical formulation comprising (i) an insulin compound, (ii) ionic zinc and (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate; wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C; which comprises adding a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• A method of improving the storage stability of an aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate; (iv)

optionally one or more buffers e.g. phosphate such as sodium phosphate; (v) optionally one or more preservatives e.g. phenol and m-cresol; (vi) optionally one or more tonicity modifiers e.g. glycerol or NaCl, and (vii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide; wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C; which comprises adding a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • A method of improving the storage stability of an aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C e.g. citrate; (iv) optionally one or more buffers e.g. phosphate such as sodium phosphate; (v) optionally one or more preservatives e.g. phenol and m-cresol; (vi) optionally one or more tonicity modifiers e.g. glycerol or NaCl, and (vii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide; which comprises adding a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM.

In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• A method of improving the storage stability of an aqueous liquid pharmaceutical formulation comprising (i) an insulin compound, (ii) ionic zinc and (iii) citrate as a zinc binding species at a concentration of 1 mM; wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C; which comprises adding a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside, wherein the insulin compound is present at a concentration of 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml or 100-<200 U/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• A method of improving the storage stability of an aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc (iii) citrate as a zinc binding species at a concentration of 1 mM or more; (iv) optionally one or more buffers e.g. phosphate such as sodium phosphate; (v) optionally one or more preservatives e.g. phenol and m-cresol; (vi) optionally one or more tonicity modifiers e.g. glycerol or NaCl, suitably NaCl e.g. at a concentration of 100-300 mM e.g. around 150 mM, and (vii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide; wherein the formulation is substantially free of EDTA and any other zinc binding species

having a logK with respect to zinc ion binding of more than 10 at 25 °C; which comprises adding a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside, wherein the insulin compound is present at a concentration of 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml or 100-<200 U/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin. • A method of improving the storage stability of an aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc (iii) citrate as a zinc binding species at a concentration of 1 mM or more; (iv) optionally one or more buffers e.g. phosphate such as sodium phosphate; (v) optionally one or more preservatives e.g. phenol and m-cresol; (vi) optionally one or more tonicity modifiers e.g. glycerol or NaCl, suitably NaCl e.g. at a concentration of 100-300 mM e.g. around 150 mM, and (vii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide; which comprises adding a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside, wherein the insulin compound is present at a concentration of 10-250 U/ml, 10-<250 U/ml, 50-250 U/ml, 50-<250 U/ml, 100-250 U/ml, 100-<250 U/ml, 10-200 U/ml, 10-<200 U/ml, 50-200 U/ml, 50-<200 U/ml, 100-200 U/ml or 100-<200 U/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin

compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• A method of improving the storage stability of an aqueous liquid pharmaceutical formulation comprising (i) an insulin compound, (ii) ionic zinc and (iii) citrate as a zinc binding species at a concentration of 1 mM or more; wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 10 at 25 °C; which comprises adding a non-ionic surfactant which is an alkyl glycoside, particularly dodecyl maltoside, wherein the insulin compound is present at a concentration of 400-1000 U/ml, >400-1000 U/ml, 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml or >900-1000 U/ml. In one embodiment, the alkyl glycoside is dodecyl maltoside at a concentration in the range 1-1000 µg/ml, e.g. 5-500 µg/ml, e.g. 10-200 µg/ml, such as 10-100 µg/ml especially around 50 µg/ml. In a further embodiment, the zinc binding species is citrate at a concentration of 1-100 mM, e.g. 15-60 mM, 20-50 mM, 20-30 mM or 30-60 mM. In a first further embodiment, the insulin compound is insulin lispro. In a second further embodiment, the insulin compound is insulin aspart. In a third further embodiment, the insulin compound is insulin glulisine. In a fourth further embodiment, the insulin compound is recombinant human insulin.
• A method of improving the storage stability of an aqueous liquid pharmaceutical formulation consisting of (i) an insulin compound, (ii) ionic zinc (iii) citrate as a zinc binding species at a concentration of 1 mM or more; (iv) optionally one or more buffers e.g. phosphate such as sodium phosphate; (v) optionally one or more preservatives e.g. phenol and m-cresol; (vi) optionally one or more tonicity modifiers e.g. glycerol or NaCl, suitably glycerol e.g. at a concentration of 100-300 mM e.g. 150-200 mM e.g. 170-180 mM or 174 mM, and (vii) optionally one or more additional active agents such as an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or

We claim:
1. An aqueous liquid pharmaceutical formulation comprising (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C, and (iv) a non-ionic surfactant which is an alkyl glycoside; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C.
2. The formulation according to claim 1, wherein the insulin compound is not insulin glargine.
3. The formulation according to claim 1, wherein the insulin compound is insulin lispro.
4. The formulation according to claim 1, wherein the insulin compound is insulin aspart.
5. The formulation according to claim 1, wherein the insulin compound is insulin glulisine.
6. The formulation according to claim 1, wherein the insulin compound is recombinant human insulin.
7. The formulation according to any one of claims 1 to 6, wherein the insulin compound is present at a concentration of 10-1000 U/ml.
8. The formulation according to claim 7, wherein the insulin compound is present at a concentration of 50-1000 U/ml.
9. The formulation according to claim 7, wherein the insulin compound is present at a concentration of 10-250 U/ml.
10. The formulation according to claim 7, wherein the insulin compound is present at a concentration of 400-1000 U/ml.
11. The formulation according to any one of claims 1 to 10, wherein the ionic zinc is present at a concentration of more than 0.05% by weight of zinc based on the weight of insulin compound in the formulation.

12. The formulation according to claim 11, wherein the ionic zinc is present at a concentration of more than 0.5% by weight of zinc based on the weight of insulin compound in the formulation.
13. The formulation according to claim 12, wherein the ionic zinc is present at a concentration of 0.5-1% by weight of zinc based on the weight of insulin compound in the formulation.
14. The formulation according to any one of claims 1 to 13, wherein the zinc binding species having a logK with respect to zinc ion binding in the range 4.5-12.3 is selected from citrate, pyrophosphate, aspartate, glutamate, cysteine, cystine, glutathione, ethylenediamine, histidine, DETA and TETA.
15. The formulation according to claim 14, wherein the zinc binding species is citrate.
16. The formulation according to claim 15, wherein the source of the citrate is citric acid.
17. The formulation according to any one of claims 1 to 16, wherein the zinc binding species having a logK with respect to zinc ion binding in the range 4.5-12.3 is present at a concentration of 1-50 mM.
18. The formulation according to any one of claims 1 to 17, wherein the molar ratio of ionic zinc to zinc binding species is 1:3 to 1:175.
19. The formulation according to any one of claims 1 to 13, wherein the zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C is a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C.
20. The formulation according to any one of claims 1 to 13, which is substantially free of zinc binding species having a logK with respect to zinc ion binding of 10-12.3 at 25 °C.
21. The formulation according to any one of claims 1 to 20, wherein the alkyl glycoside is selected from the group consisting of dodecyl maltoside, dodecyl glucoside, octyl glucoside, octyl maltoside, decyl glucoside, decyl maltoside, decyl glucopyranoside, tridecyl glucoside, tridecyl maltoside, tetradecyl glucoside, tetradecyl maltoside, hexadecyl glucoside, hexadecyl maltoside,

sucrose monooctanoate, sucrose monodecanoate, sucrose monododecanoate, sucrose monotridecanoate, sucrose monotetradecanoate and sucrose monohexadecanoate.
22. The formulation according to claim 21, wherein the alkyl glycoside is dodecyl maltoside or decyl glucopyranoside.
23. The formulation according to claim 22, wherein the alkyl glycoside is dodecyl maltoside.
24. The formulation according to any one of claims 1 to 23, wherein the non-ionic surfactant is present at a concentration of 1-1000 µg/ml e.g. 5-500 µg/ml, 10-200 µg/ml, 10-100 µg/ml or around 50 µg/ml.
25. The formulation according to claim 24, wherien the non-ionic surfactant is present at a concentration of 10-400 µg/ml e.g. 20-400 µg/ml, 50-400 µg/ml, 10-300 µg/ml, 20-300 µg/ml, 50-300 µg/ml, 10-200 µg/ml, 20-200 µg/ml, 50-200 µg/ml, 10-100 µg/ml, 20-100 µg/ml or 50-100 µg/ml.
26. The formulation according to any one of claims 1 to 25, further comprising a tonicity modifying agent.
27. The formulation according to claim 26, wherein the tonicity modifying agent is an uncharged tonicity modifying agent.
28. The formulation according to claim 27, wherein the uncharged tonicity modifying agent is selected from the group consisting of trehalose, mannitol, glycerol and 1,2-propanediol.
29. The formulation according to claim 28, wherein the uncharged tonicity modifying agent is glycerol.
30. The formulation according to claim 26, wherein the tonicity modifying agent is a charged tonicity modifying agent.
31. The formulation according to claim 30, wherein the charged tonicity modifying agent is sodium chloride.
32. The formulation according to claim 30 or claim 31, wherein the chloride is present at a concentration of >60 mM e.g. >65 mM, >75 mM, >80 mM, >90 mM, >100 mM, >120 mM or >140 mM.
33. The formulation according to claim 10, wherein the ionic strength of the formulation excluding the zinc binding species and the insulin compound is

<40 mM, e.g. <30 mM, <20 mM or <10 mM, wherein ionic strength is calculated according to the formula Ia:

in which cx is molar concentration of ion x (mol L-1), zx is the absolute value of the charge of ion x and the sum covers all ions (n) present in the formulation.
34. The formulation according to any one of claims 1 to 33, wherein the composition is substantially isotonic.
35. The formulation according to any one of claims 1 to 34, wherein the pH is in the range 5.5 to 9.0.
36. The formulation according to claim 35, wherein the pH is in the range 7.0 to 7.5 e.g. 7.4.
37. The formulation according to claim 35, wherein the pH is in the range 7.6 to 8.0 e.g. 7.8.
38. A formulation according to claim 36 or claim 37, which comprises a phosphate buffer e.g. sodium phosphate.
39. The formulation according to any of claims 1 to 38, further comprising a preservative.
40. The formulation according to claim 39, wherein the preservative is selected from the group consisting of phenol, m-cresol, chlorocresol, benzyl alcohol, propylparaben, methylparaben, benzalkonium chloride and benzethonium chloride.
41. A formulation according to any one of claims 1 to 40, further comprising nicotinamide.
42. A formulation according to any one of claims 1 to 41, further comprising nicotinic acid or a salt thereof.
43. A formulation according to any one of claims 1 to 42, further comprising treprostinil or a salt thereof.
44. An aqueous liquid pharmaceutical formulation according to claim 1, comprising (i) an insulin compound at a concentration of 50-500 U/ml (ii) ionic zinc, (iii) citrate as a zinc binding species at a concentration of 1 mM or more, and (iv) a non-ionic surfactant which is an alkylglycoside; and wherein the formulation is

substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C.
45. A formulation according to claim 44, wherein the citrate is present in the formulation at a concentration of 10-30 mM.
46. An aqueous liquid pharmaceutical formulation according to claim 1 comprising (i) an insulin compound at a concentration of 400-1000 U/ml e.g. 500-1000 U/ml (ii) ionic zinc, (iii) citrate as a zinc binding species at a concentration of 1 mM or more, and (iv) a non-ionic surfactant which is an alkyl glycoside; and wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C.
47. A formulation according to claim 46, wherein the citrate is present in the formulation at a concentration of 30-50 mM.
48. A formulation according to any one of claims 1 to 47, for use in the treatment of a subject suffering from diabetes mellitus.
49. A method of treatment of diabetes mellitus which comprises administering to a subject in need thereof an effective amount of a formulation according to any one of claims 1 to 47.
50. A container containing one dose or a plurality of doses of the formulation according to any one of claims 1 to 47.
51. An injection device for single or multiple use comprising a container containing one dose or a plurality of doses of the formulation according to any one of claims 1 to 47 together with an injection needle.
52. A medical device comprising a reservoir comprising a plurality of doses of the formulation according to any one of claims 1 to 47 and a pump adapted for automatic or remote operation such that upon automatic or remote operation one or more doses of the formulation is administered to the body.
53. A dry solid pharmaceutical composition suitable for reconstitution with an aqueous medium which comprises, following reconstitution, (i) an insulin compound, (ii) ionic zinc, (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C, and (iv) a non-ionic surfactant which is an alkyl glycoside; and wherein the composition is substantially free of EDTA and any

other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C.
54. A method of preparing a formulation according to any one of claims 1 to 47 which comprises dissolving a dry solid pharmaceutical composition according to claim 53 in an aqueous medium.
55. A method of improving the storage stability of an aqueous liquid pharmaceutical formulation comprising (i) an insulin compound, (ii) ionic zinc and (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C; wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C; which comprises adding a non-ionic surfactant which is an alkyl glycoside to the formulation.
56. Use of a non-ionic surfactant which is an alkyl glycoside to improve the storage stability of an aqueous liquid pharmaceutical formulation comprising (i) an insulin compound, (ii) ionic zinc and (iii) a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C; wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C.
57. A composition, method or use according to any one of claims 53-56, wherein the zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C is a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-10 at 25 °C.
58. A composition, method or use according to any one of claims 53-57, wherein the formulation is substantially free of zinc binding species having a logK with respect to zinc ion binding of 10-12.3 at 25 °C.
59. An aqueous liquid pharmaceutical formulation comprising (i) an insulin compound at a concentration of 400-1000 U/ml and (ii) ionic zinc;
wherein the formulation is bioequivalent to a corresponding formulation comprising the insulin compound at a concentration of 100 U/ml.

60. A formulation according to claim 59, wherein the insulin compound is present at a concentration of >400-1000 U/ml, e.g. 500-1000 U/ml, >500-1000 U/ml, 600-1000 U/ml, >600-1000 U/ml, 700-1000 U/ml, >700-1000 U/ml, 750-1000 U/ml, >750-1000 U/ml, 800-1000 U/ml, >800-1000 U/ml, 900-1000 U/ml, >900-1000 U/ml e.g. 1000 U/ml.
61. A formulation according to claim 59, comprising (i) insulin lispro at a concentration of 500-1000 U/ml and (ii) ionic zinc;
wherein the formulation is bioequivalent to an aqueous formulation consisting of: insulin lispro (100 U/ml), sodium phosphate (13.2 mM), glycerol (174 mM), m-cresol (29 mM), ionic zinc (19.7 µg/ml, excluding counter-ion) adjusted to pH 7.3.
62. A formulation according to claim 59, comprising (i) insulin aspart at a
concentration of 500-1000 U/ml and (ii) ionic zinc;
wherein the formulation is bioequivalent to an aqueous formulation consisting of: insulin aspart (100 U/ml), sodium phosphate (7 mM), glycerol (174 mM), sodium chloride (10 mM), phenol (15.9 mM), m-cresol (15.9 mM) and ionic zinc (19.7 µg/ml, excluding counter-anion) adjusted to pH 7.4.
63. A formulation according to any one of claims 59 to 62, wherein the total percentage increase in related species during storage (e.g. at 30 oC for 1, 2 or 3 months) is no higher than that of a corresponding formulation comprising the insulin compound at a concentration of 100 U/ml.
64. A formulation according to any one of claims 59 to 63, wherein the formulation comprises a zinc binding species at a concentration of 1 mM or more selected from species having a logK with respect to zinc ion binding in the range 4.5-12.3 at 25 °C.
65. A formulation according to claim 64, wherein the zinc binding species is citrate.
66. A formulation according to claim 64 or claim 65, wherein the concentration of zinc binding species is from 30 mM to 50 mM.
67. A formulation according to any one of claims 59 to 66, wherein the formulation comprises a non-ionic surfactant.

68. A formulation according to any one of claims 59 to 67, wherein the formulation is substantially free of EDTA and any other zinc binding species having a logK with respect to zinc ion binding of more than 12.3 at 25 °C.
69. A formulation according to any one of claims 59 to 68, wherein a Student’s t-test applied to the Tmax of the aqueous liquid pharmaceutical formulation and the corresponding formulation provides a p-value of ≥0.05.
70. A formulation according to any one of claims 1 to 47 and 59 to 69, wherein the formulation does not contain a vasodilator e.g. does not contain treprostinil, nicotinamide, nicotinic acid or a salt thereof.
71. A formulation according to any one of claims 1 to 47 and 59 to 70, wherein the formulation further comprises an additional therapeutically active agent e.g. of use in the treatment of diabetes.
72. A formulation according to claim 71, wherein the additional active agent is selected from the group consisting of an amylin analogue such as pramlintide or a GLP-1 agonist such as liraglutide, dulaglutide, albiglutide, exenatide or lixisenatide.
73. A formulation according to any one of claims 1 to 47 and 59 to 72, wherein the formulation is co-administered with a long acting insulin such as insulin glargine or insulin degludec.