DESC:STABLE LIQUID COMPOSITIONS OF DAPTOMYCIN

FIELD OF THE INVENTION
The present invention relates to a stable, aqueous liquid composition comprising, daptomycin or its acceptable salt thereof at a concentration of 26mg/mL or above, chelating agents, and/or glacial acetic acid and calcium hydroxide to stabilize the composition.
BACKGROUND OF THE INVENTION
Daptomycin, a cyclic lipopeptide antibacterial agent derived from the fermentation of Streptomyces roseosporus. Daptomycin is used for the treatment of various bacterial infections caused by Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE). It was discovered in the early 1980s, at Eli Lilly and Company. Daptomycin was initially developed in the late 1980s and early 1990s but was ultimately shelved due to concerns regarding adverse effects, in particular drug-induced myopathy.
Daptomycin is approved as Cubicin® and Cubicin® RF to Cubist Pharmaceuticals. CUBICIN is supplied in a single-dose vial as a sterile, preservative-free, pale yellow to light brown, lyophilized cake containing approximately 500 mg of daptomycin for intravenous (IV) use following reconstitution with 0.9% sodium chloride injection.
CUBICIN is supplied in single-dose vials, each containing 500 mg daptomycin as a sterile, lyophilized powder. The contents of a CUBICIN vial should be reconstituted, using aseptic technique, to 50 mg/mL. This 50mg/mL of the drug is given either as an intravenous injection for 2 minutes for adults or intravenous infusion over 30 minutes in 0.9% sodium chloride.
To obtain 50mg/mL concentration, the 500mg/vial is reconstituted with 10mL of 0.9% sodium chloride injection, further to administer as IV infusion, this 50mg/mL concentrate should be further diluted, into a 50 mL IV infusion bag containing 0.9% sodium chloride injection. During this reconstitution procedure precaution and extra care has to be taken as to avoid foaming as the drug degrades if foam is formed. This can be done by avoiding vigorous agitation of the vial, slowly transfer 10 mL of 0.9% sodium chloride injection through the centre of the rubber stopper into the CUBICIN vial, pointing the transfer needle toward the wall of the vial. Ensure that all of the CUBICIN powder is wetted by gently rotating the vial. Allow the wetted product to stand undisturbed for 10 minutes and gently rotate or swirl the vial contents for a few minutes, as needed, to obtain a completely reconstituted solution.
Cubicin® RF is supplied in single-dose vials, each containing 500 mg daptomycin as a sterile, lyophilized powder. The contents of a CUBICIN® RF vial should be reconstituted, within the vial only with either sterile water for injection or bacteriostatic water for injection to 50 mg/mL. To obtain 50mg/mL concentration, the 500mg/vial is reconstituted with 10 mL of sterile water for injection or bacteriostatic water for injection, further to administer as IV infusion, this 50mg/mL concentrate should be further diluted, into a 50 mL IV infusion bag containing 0.9% sodium chloride injection. The appropriate volume of the reconstituted CUBICIN RF (concentration of 50 mg/mL) should be further diluted, using aseptic technique, into a 50 mL IV infusion bag containing 0.9% sodium chloride injection.
The above reconstituted and diluted solution are given as IV concentrate for 2 minutes to adults, infusion of over 30 minutes to adults and infusion of over 30/60 minutes to paediatrics at varying infusion rates. The marketed lyophilized products are having too many tedious steps of reconstitution, dilution and precautions have to be taken at each and every step to avoid foaming, and if foaming occurs the solution will get degraded.
US pat. no. 9138456 discloses Cubicin RF composition, it covers a solid daptomycin composition, wherein said composition is prepared by lyophilizing an aqueous daptomycin solution comprising daptomycin and sucrose.
To avoid the above intricacies, few new compositions have been developed, US pat. no. 8431539 B2 discloses a long term storage stable daptomycin-containing composition, comprising, daptomycin or a pharmaceutically acceptable salt thereof at a concentration of less than or equal to about 25 mg/mL, buffer having an acidic functional group such as: ADA (N-(2-acetamido)-2-iminodiacetic acid), PIPES (piperazine-N,N'-bis(2-ethanesulfonic acid)); calcium hydroxide, wherein the above composition has less than 10% total impurities after about 18 months of storage at a temperature of from about 5° C. to about 25° C.
WO/2016/59592 A1 discloses a stable, non-aqueous and ready-to-use injectable composition of a peptide drug or a pharmaceutically acceptable salt or a co-crystal thereof comprising, a peptide drug or a pharmaceutically acceptable salt or a co-crystal thereof; wherein the said peptide drug is other than bivalirudin; a non-aqueous solvent system such as ethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, glycerol and polyethylene glycol or a mixture thereof; optionally a polyol is selected from the group consisting of glycerin, sucrose, lactose, glucose, fructose, arabinose, xylose, ribose, mannose; optionally a pH adjusting agent; and optionally an antioxidant selected from butylated hydroxytoluene, sodium metabisulphite, acetylcysteine, ascorbyl palmitate, butylated hydroxyanisole, monothioglycerol, potassium nitrate, ascorbic acid or sodium ascorbate, sodium formaldehyde sulfoxylate, sodium bisulfite, vitamin E.
WO/2016/059587 A1 discloses a stable, non-aqueous and ready-to-use injectable composition of a peptide drug or a pharmaceutically acceptable salt or a co-crystal thereof comprising a pharmaceutical active agent or a pharmaceutically acceptable salt or a co-crystal thereof; a non-aqueous solvent system; optionally a polyol; optionally a pH adjusting agent; and optionally an antioxidant.
Further considering peptide chemistry and characterisation of impurities of daptomycin, it has been evaluated and impurity profile has been disclosed. The main impurities include 3 fermentation process related impurities and three degradation products namely anhydro-daptomycin, ß-aspartyl isomer and lactone hydrolysis product of daptomycin. The main degradants of daptomycin are the hydrolysis product of daptomycin, the ß-isomer of daptomycin and anhydro-daptomycin. The hydrolysis product (ring opening compound) appears as the main impurity at a Relative Retention Time (RRT) of about 0.66, the ß-isomer of daptomycin appears as the main impurity at an RRT of about 0.97 and anhydro daptomycin appears as the main impurity at an RRT of about 1.1.
Considering the above intricacies and challenges of product development, the inventors of present invention surprisingly found ways to stabilize the daptomycin in aqueous liquid composition without compromising on the stability aspects to give a stable composition of daptomycin.

SUMMARY OF THE INVENTION
The objective of the present invention is to prepare a stable, aqueous liquid composition comprising daptomycin or its acceptable salt thereof at a concentration of 26mg/mL or above, glacial acetic acid and/or calcium hydroxide to to adjust the pH, wherein the composition is free of sugars.
The composition includes a stable, aqueous liquid composition comprising:
- daptomycin or its acceptable salt thereof at a concentration of 26mg/mL or above,
- glacial acetic acid and/or calcium hydroxide to adjust the pH;
- wherein daptomycin to glacial acetic acid is in a stoichiometric ratio of about 0.75 to about 1.4:0.2 to 2.5;
- wherein the daptomycin to calcium hydroxide in a stoichiometric ratio of about 0.75 to about 1.4:0.2 to 2.5;
the composition is free of sugars.
The composition according to above embodiment, wherein the daptomycin is in the range from about 26mg/mL to about 100mg/mL.
The composition according to previous embodiment, wherein daptomycin to glacial acetic acid is in a stoichiometric ratio of about 0.6 to 1.5 :0.3 to 4.0.
The composition according to previous embodiment, wherein the daptomycin to calcium hydroxide in a stoichiometric ratio of about 0.6 to 1.5 :0.15 to 3.0.
The composition according to previous embodiment, wherein the composition is having less than 10% of total impurities; wherein the impurities comprise of anhydro impurity, lactone hydrolysis, and beta-isomer.
The composition according to previous embodiments, may further comprise of other excipients such as solvents, co-solvents, antioxidants, and/or preservatives, buffers, stabilizers, pH modifiers, chelating agents and the like or mixtures thereof.
The composition according to previous embodiments, wherein the composition is used to treat daptomycin related sensitive diseases.

DETAILED DESCRIPTION OF THE INVENTION
The term "active ingredient” or “drug" refers to a substance that has a physiological effect when ingested or otherwise introduced into the body, in particular or a chemical substance used in the treatment, cure, prevention, or diagnosis of disease or used to otherwise enhance physical or mental well-being.
The term "excipient" or "pharmaceutically acceptable excipient" or “adjuvant” means a component of a pharmaceutical product that is not a pharmacologically active ingredient, such as diluent, bulking agent, carrier, acidifying agent, pH modifier, chelating agent, solvent, co-solvent, tonicity modifier, antioxidant, preservative and the like added to a drug to increase or aid its effect. The excipients or adjuvants that are useful in preparing pharmaceutical compositions are generally safe, non- toxic, and neither biologically nor otherwise undesirable, and are acceptable for veterinary use as well as human pharmaceutical use. The term includes one or more excipients or adjuvants.
The term "composition" is intended to encompass a combination including active ingredients and pharmaceutically acceptable excipients, as well as any product which results, directly or indirectly, from combination, complexation, or aggregation of any two or more of the ingredients, or from dissociation of one or more of the ingredients, or from other types of reactions or interactions involving one or more of the ingredients.
The term “formulation” or “dosage form” or “composition” refers to finished pharmaceutical products that are suitable for administration, including, but not limited to, injections, etc.
The term "optional" or "optionally" means that the subsequently described element, component or circumstance may or may not be present, so that the description includes instances where the element, component, or circumstance is included and instances where it is not.
The term “stability” or “stable” as used herein includes both physical and chemical stability. Stability parameters include but not limited to potency, stable pH value and other physico-chemical parameters.
"Carrier" or "vehicle” or “solvent” as used herein refers to pharmacologically inert materials that provide a more or less fluid matrix, suitable for topical drug administration. Carriers and vehicles useful herein include any such materials known in the art, which are nontoxic and do not interact with other components of a pharmaceutical formulation or drug delivery system in a deleterious manner. The formulations of the present invention are particularly suitable for parenteral administration. Formulations suitable for parenteral dosage forms such as injectable like intravenous, intramuscular or subcutaneous, implants and the like. Other parenteral ingredients used in the formulation are generally those commonly used and recognized by persons skilled in the art of parenteral formulations.
"Pharmaceutically-acceptable salts" refer to derivatives of the disclosed compounds wherein the parent compound is modified by making acid or base salts, solvate, hydrate, esters and the like thereof. Pharmaceutically-acceptable salt forms of compounds provided herein are synthesized from the parent compound which contains a basic or acidic moiety by conventional chemical methods. Pharmaceutically acceptable salts are those forms of compounds, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio.
Any recitation of ranges of values set forth below is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. Furthermore, all references, including patent applications, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The present invention relates to a stable, aqueous liquid composition comprising daptomycin or its acceptable salt thereof and other excipients.
In one embodiment the invention relates to a stable, aqueous liquid composition comprising:
- daptomycin or its acceptable salt thereof at a concentration of 26mg/mL or above,
- glacial acetic acid and calcium hydroxide to adjust the pH of the composition;
wherein the composition is free of sugars.
The composition, wherein the daptomycin is in the range from about 26mg/mL to about 100mg/mL; for example, from about 30 mg/mL to about 80mg/mL; further from about 40 mg/mL to about 70 mg/mL.
Daptomycin, a cyclic lipopeptide with four free carboxyl groups are highly unstable, the present inventors have tried to overcome this problem by using glacial acetic acid and calcium hydroxide. The ratio of both excipients play an important role to adjust the pH and help to obtain a stable, effective aqueous compositions.
In one more embodiment, the daptomycin to glacial acetic acid is in a stoichiometric ratio of about 0.5 to 2:0.2 to 5; for example, between about 0.6 to 1.5:0.3 to 4; for example, between about 0.75 to 1.4:0.5 to 2.5.
In one more embodiment, the daptomycin to calcium hydroxide is in a stoichiometric ratio of about 0.5 to 2:0.1 to 3.5; for example, between about 0.6 to 1.5:0.15 to 3; for example, between about 0.75 to 1.4:0.2 to 2.5.
The ratio of daptomycin to acetic acid and/or calcium hydroxide is important to adjust the pH and provide a stable composition. Both these excipients are used as pH modifiers or stabilizers. The other pH modifiers include, but not limited to magnesium hydroxide, calcium hydroxide, sodium hydroxide, and the like or mixtures thereof.
Stabilizers include but not limited to amino acids, such as arginine, lysine, aspargine, glysine, aspartic acid, and the like or mixtures thereof.
Chelating agents include but not limited to ethylene diamine tetraacetic acid (EDTA), ethylene glycol-bis(beta-aminoethyl ether)-N,N,N’, N’-tetraacetic acid (EGTA) and 8-Amino-2-[(2-amino-5-methylphenoxy) methyl]-6-methoxyquinoline-N,N,N’N’-tetraacetic acid, tetrapotassium salt (QUIN-2). Chelating agents may be selected from the above group or other chelating agents known in the art, its pharmaceutically acceptable salts, or solvates, or derivatives, or mixtures thereof.
In another embodiment, the composition according to above embodiments is free of sugars such as mannitol, dextrose, sucrose, and the like or mixtures thereof.
Further the compositions disclosed in the above aspects may comprise of other excipients, but not limited to solvents, co-solvents, antioxidants, and/or preservatives, chelating agents, buffers, and the like or mixtures thereof.
Solvents and/or co-solvents include, but are not limited to water, water for injection (WFI) and the like, wherein water or water for injection is free or substantially free of oxygen.
Antioxidant and/or preservative include but not limited to monothioglycerol, L- cysteine, thioglycolic acid, sodium metabisulfite, ascorbic acid, sodium ethylenediaminetetraacetic acid, monoethanolamine gentisate, sodium formaldehyde sulfoxylate, sodium bisulfate, butylated hydroxy toluene (BHT), butylated hydroxy anisole (BHA), phenylmercuric nitrate, thiomersal, benzalkonium chloride, benzethonium chloride, phenol, cresol or chlorobutanol.
Buffers include but not limited to acetate, citrate, tartrate, phosphate, benzoate, bicarbonate, organic amines and the like or any mixtures thereof. Organic amines include but not limited to Tris(hydroxymethyl) aminomethane, ?- (2 - Acetamido) -2 –aminoethanesulfonic acid, N-(2-(Acetamido)imino)diacetic acid, 2-?min?-2- methyl-1-propanol, 2-Amino-2-methyl-l,3-propanediol, N-(l,l-Dimethyl-2-hydroxyethyl)-3-amino-2-hydroxypropanesulfonic acid, N,N-Bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, N,N-Bis(2-hydroxyethyl)glycine, 2,2'-(Propane-l,3-diyldiimino)bis[2-(hydroxymethyl)propane-l, 3-diol], 2-[Bis(2-hydroxyethyl)imino]-2-(hydroxymethyl)-1,3-propanediol, 2- Amino ethanol, (2R,3R,4R,5S)-6-Methylaminohexane-l,2,3,4,5-pentol, 2,2',2"-Nitrilotriethanol.
Inventors of this invention have studied that pH of this composition plays an important role in stabilizing the composition. Hence pH is maintained at about 4.5 to about 8.5, for example, pH is between about 5.0 to about 7.0; for example, between about 5.5 to about 6.5.
In one embodiment, the compositions of daptomycin having a concentration of about 26mg/ml and above comprises of 10% or less impurities or related substances, to obtain a stable composition by maintaining the pH of the composition.
In an embodiment the composition comprises of daptomycin, calcium hydroxide, optionally antioxidant, glacial acetic acid, water for injection.
In another embodiment, the compositions can be filled or presented in required volumes such as 1mL, 2 mL, 2.5mL, 3mL, 3.5mL, 4mL, 4.5mL, 5mL, 5.5mL, 6mL, 6.5mL, 7mL, 7.5mL, 8mL, 8.5mL, 9mL, 9.5mL, 10mL and the like to give a flexibility to the healthcare provider.
The proposed compositions can be presented in ampoules, vials, prefilled syringes made of glass or plastic.
In an embodiment, considering the prior literature as aqueous compositions showed instability, aqueous and non-aqueous compositions were developed to understand the stability.
The above non-aqueous composition F1 was developed and stability study showed that impurity E and beta isomer highly increased. As the composition was unstable, the compositions were discontinued from further studies.
As non-aqueous compositions were not stable, hence further studies were conducted with aqueous compositions F2. The stability data of composition 2 at accelerated condition for 10 days showed an increase in anhydro-daptomycin impurity at about 1.65%. Considering the stability data, it infers that sodium hydroxide was not suitable for proposed composition. Hence the proposed composition was discontinued from further studies.
In another embodiment, other compositions were tried using sugars, such as mannitol, sucrose, and other excipients.
Composition F3 with sucrose, calcium hydroxide and hydrochloric acid. Stability studies were performed and the results showed that anhydro-daptomycin impurity was increased by using hydrochloric acid used as pH adjusting agent. pH was adjusted at 6.90. It is inferred that low concentration of calcium hydroxide and adjusting hydrochloric acid is not stabilizing the composition. Hence further studies were discontinued.
Stability studies with composition F4 were performed and the results showed that the related substances were less as compared with F3 compositions and hence, glacial acetic acid seem to be better than hydrochloric acid as pH adjusting agent, pH was adjusted at 6.90. Anhydro-daptomycin was controlled by using glacial acetic acid. Hence further studies were continued with glacial acetic acid.
Composition F5 were developed comprising sucrose, high concentration of calcium hydroxide and glacial acetic acid. Stability studies indicate that sucrose is not reducing the impurity levels as both lactone hydrolysis product and ß-isomer of daptomycin is increased. Hence sucrose was discontinued from further studies.
Sucrose was replaced with mannitol in composition F6 and pH was adjusted at 6.65. Stability results indicate that ß-isomer of daptomycin impurity increased and related substances also increased. Hence further studies were discontinued.
Calcium hydroxide was replaced with calcium edetate and also acetic acid was not used in this composition F7, sodium hydroxide was used to adjust the pH to 6.65. However, related substances were increased as compared to previous compositions. Hence mannitol was discontinued from further studies.
Considering the above studies, it was inferred that non-aqueous compositions and aqueous compositions with or without sugars were not helping to get a stable composition. Hence inventors of this invention developed other compositions using antioxidants in its compositions and varying the pH of the compositions using glacial acetic acid and calcium hydroxide.
Compositions F8 to F15 were developed to understand the stability, after addition of monothioglycerol as antioxidant and pH of compositions were adjusted from 4.9 to 7.4. Stability data of F8 indicate that ß-isomer of daptomycin and lactone hydrolysis product were increased at stress condition at pH 6.65.
Stability data of F9 indicates that change in pH from 6.65 to 4.9 increases anhydro-daptomycin impurity and also related substances were increased.
Stability data of F10 indicates that at pH 5.4 anhydro-daptomycin impurity was decreased in comparison at pH 4.9, however a slight increase of beta-isomer and anhydro-daptomycin.
Stability data of F11 infers that at pH 6.40 lactone hydrolysis product were increased, however, the related substances were within the limits.
Stability data of F12 infers that at pH 6.90 all 3 major impurities lactone hydrolysis product, ß-isomer and anhydro-daptomycin increased, thereby increasing the related substances as well.
Stability data of F13 infers that at pH 7.40, 2 impurities lactone hydrolysis product, and ß-isomer increased, thereby increasing the related substances also.
Stability data of F14 indicates that compositions at pH 5.90 related substances were relatively less, when compared to the compositions at higher or lower pH. Further composition F15 was studied to understand the composition lacking monothioglycerol, the composition was found to be stable and comparable to the F14 composition.
Considering the above compositions, it was found that aqueous compositions were found to be stable by using stoichiometric ratio of calcium hydroxide and glacial acetic acid. However, lower concentration of calcium hydroxide in F3 & F4 compositions and increase in concentration of calcium hydroxide in F5 to F15 compositions played an important role in adjusting the pH and indirectly stabilizing the compositions.
The proposed composition according to preceding emodiments is used to treat daptomycin sensitive diseases such as Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-susceptible
Staphylococcus aureus (MSSA), Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus dysgalactiae subspecies equisimilis, and Enterococcusfaecalis (vancomycin-susceptible isolates only) in complicated skin infections and bloodstream infections (bacteremia), including rightsided /infective endocarditis and the like.
The compositions and stability data details are presented in below Examples from tables 1 to 5.
Example 1:
Table 1: Compositions F1 to F7
S. No Ingredient Compositions Quantities (mg/ml)
F1 F2 F3 F4 F5 F6 F7
1 Daptomycin 50 100 50 50 50 50 50
2 Propylene glycol 940 - - - - - -
3 Sucrose - - 90 90 95 - -
4 Mannitol - - - - - 100 100
5 Calcium Hydroxide* - - 10 10 20 20 -
6 Monothioglycerol 5 - - - - - -
7 Edetate Calcium disodium - - - - - - 50
8 Bis-tris buffer 5 - - - - - -
9 Calcium Hydroxide & Hydrochloric acid - - q.s.
pH 6.9 - - - -
10 Calcium Hydroxide & Glacial Acetic acid - - - q.s.
pH 6.9 q.s.
pH 6.65 q.s.
pH 6.65 -
11 Sodium hydroxide - q.s.
pH 6.8 - - - - q.s.
pH 6.65
12 Water for injection - q.s. q.s. q.s. q.s. q.s. q.s.
13 Nitrogen - q.s. q.s. q.s. q.s. q.s. q.s.
*- required quantity is used to adjust the pH
Table 2: Stability details of Compositions F1 to F7
Impurity Conditions % impurity
F1 F2 F3 F4 F5 F6 F7
Lactone Hydrolysis
Initial 0.40 0.26 0.46 0.743 0.3 0.26 0.31
50°C 1-DAY ND ND ND ND 3.67 3.65 3.41
Beta-Isomer
Initial 0.14 0.12 1.03 1.99 0.7 0.00 0.45
50°C 1-DAY ND ND ND ND 3.37 3.59 14.37
Anhydro- daptomycin Initial ND 0.67 1.41 0.285 1.15 1.26 1.38
50°C 1-DAY NP NP NP NP 0.55 0.62 4.93
Total Impurities Initial 5.21 3.18 4.993 4.416 4.31 3.72 3.72
50°C 1-DAY NA NA NA NA 10.71 10.13 27.40

Considering the above studies, it was inferred that aqueous compositions with or without sugars were not helping to get a stable composition. Hence inventors of this invention developed other compositions using antioxidants in its compositions and varying the pH of the compositions using glacial acetic acid and calcium hydroxide.
Example 2:
Table 3: Compositions F8 to F15
S. No Ingredient Compositions Quantities (mg/ml)
F8 F9 F10 F11 F12 F13 F14 F15
1 Daptomycin 50 50 50 50 50 50 50 50
2 Calcium Hydroxide 20 20 20 20 20 20 20 20
3 Monothioglycerol 5 5 5 5 5 5 5 -
4 Calcium Hydroxide & Glacial Acetic acid q.s.
pH 6.65 q.s.
pH 4.9 q.s.
pH 5.4 q.s.
pH 6.4 q.s.
pH 6.9 q.s.
pH 7.4 q.s.
pH 5.9 q.s.
pH 5.9
5 Water for injection q.s. q.s. q.s. q.s. q.s. q.s. q.s. q.s.
6 Nitrogen q.s. q.s. q.s. q.s. q.s. q.s. q.s. q.s.

Table 4: Stability details of Compositions F8 to F15
Impurity Conditions % impurity
F8 F9 F10 F11 F12 F13 F14 F15
Lactone Hydrolysis Initial 0.24 0.24 0.29 0.32 0.43 0.28 0.54 0.3
50°C 1-DAY 3.2 0.63 0.74 2.59 5.61 10.6 1.28 1.4
2-8°C 6M 0.99 * * 0.97 2.43 * 0.85 1.0
2-8°C 9M - - - 1.21 - - 1.16 -
2-8°C 12M - - - 1.51 - - - -
Beta- Isomer Initial 0.41 0.27 0.30 0.38 0.65 0.4 0.04 0.00
50°C 1-DAY 2.72 2.08 2.25 2.43 2.52 3.28 2.32 2.75
2-8°C 6M 4.06 * * 3.54 2.86 * 4.06 3.22
2-8°C 9M - - - 4.39 - - 5.23 -
2-8°C 12M - - - 5.38 - - - -
Anhydro- daptomycin Initial 1.31 1.45 1.4 1.38 0.69 1.29 1.33 1.23
50°C 1-DAY 0.35 7.63 4.99 0.52 0.25 0.22 1.26 2.02
2-8°C 6M 1.19 * * 0.74 0.39 * 1.19 0.92
2-8°C 9M - - - 0.73 - - 1.25 -
2-8°C 12M - - - 0.75 - - - -
Total Impurities Initial 3.94 3.72 3.38 3.40 3.45 3.77 4.12 3.24
50°C 1-DAY 9.46 12.72 10.18 7.83 11.17 16.73 7.51 8.01
2-8°C 6M 8.01 * * 7.42 8.00 * 8.01 6.94
2-8°C 9M - - - 8.39 - - 9.92 -
2-8°C 12M - - - 10.15 - - - -
*as per above tabulated data, F9, F10 & F13 formulation are higher impurity profile at 50°C stress study, F9, F10 & F13 batches are discontinued from stability.

Example 3:
Considering the above observations of F14 compositions, inventors have optimized the composition and their physical and chemical observations are given in the below tables 5A and 5B.

Table 5A: Optimized F14 Composition
Parameters Initial 2-8oC-3M
Description * *
pH 5.8 5.85
Osmolality (mOsm/kg) 495 497
Light transmission 97.932 98.396
Assay of Daptomycin 102.0 98.2
Assay of Monothioglycerol 92.0 86.5
Related Substances
Impurity A 0.10 0.10
Lactone Hydrolysis 0.32 0.86
Impurity B 0.02 0.03
Beta isomer 0.37 2.43
Impurity C 0.31 0.45
Impurity D 0.35 0.34
Impurity E 0.11 0.07
Anhydro-Daptomycin 1.35 0.55
Impurity F ND 0.02
Total Impurities 3.42 5.53
*Pale yellow colour solution

Table 5B: Optimized F14 Composition
Parameters Initial 2-8°C 3M
Description * *
pH 5.6 5.52
Osmolality (mOsm/kg) 467 474
Light transmission 98.619 98.413
Assay of Daptomycin 104.2 101.4
Assay Monothioglycerol 97.5 96.5
Related substances
Impurity A 0.11 0.09
Lactone Hydrolysis Product 0.54 0.65
Impurity B 0.02 0.04
Beta isomer 0.04 2.58
Impurity C 0.20 0.45
Impurity D 0.33 0.32
Impurity E 0.14 0.10
Anhydro-Daptomycin 1.33 1.22
Impurity F ND 0.03
Total Impurities (%) 4.12 6.24
*Pale yellow colour solution

Date: August 31, 2019 Signature:___________________
Name: Dr. M S MOHAN,
MANAGING DIRECTOR
,CLAIMS:We Claim,
1. A stable, aqueous liquid composition comprising:
- daptomycin or its acceptable salt thereof at a concentration of 26mg/mL or above,
- glacial acetic acid and/or calcium hydroxide to adjust the pH;
- wherein daptomycin to glacial acetic acid is in a stoichiometric ratio of about 0.75 to about 1.4:0.2 to 2.5;
- wherein the daptomycin to calcium hydroxide in a stoichiometric ratio of about 0.75 to about 1.4:0.2 to 2.5;
the composition is free of sugars.
2. The composition according to claim 1, wherein the daptomycin is in the range from about 26mg/mL to about 100mg/mL.
3. The composition according to claim 1, wherein daptomycin to glacial acetic acid is in a stoichiometric ratio of about 0.6 to 1.5 :0.3 to 4.0.
4. The composition according to claim 1, wherein the daptomycin to calcium hydroxide in a stoichiometric ratio of about 0.6 to 1.5 :0.15 to 3.0.
5. The composition according to claim 1, wherein the composition is having less than 10% of total impurities; wherein the impurities comprise of anhydro impurity, lactone hydrolysis, and beta-isomer.
6. The composition according to preceding claims, may further comprise of other excipients such as solvents, co-solvents, antioxidants, and/or preservatives, buffers, stabilizers, pH modifiers, chelating agents and the like or mixtures thereof.
7. The composition according to preceding claims wherein the composition is used to treat daptomycin related sensitive diseases.