DESC:
Field of the invention:
The present invention relates to a stable aqueous ready-to-dilute pharmaceutical composition comprising dalbavancin or physiologically acceptable salts and other pharmaceutically acceptable excipients such as stabilizers, tonicity agents/co-solvents and solvents. The formulation has minimal ingredients and shows an acceptable impurity profile during long term stability conditions.

Background:
Dalbavancin is a second-generation lipoglycopeptide bactericidal antibiotic approved for the treatment of patients with adult and pediatric patients with acute bacterial skin and skin structure infections (ABSSSI) caused by certain strains of Gram-positive bacteria, including, e.g., methicillin-resistant Staphylococcus aureus (CLSA) and methicillin-resistant Staphylococcus epidermidis (CLSE). Like other glycopeptides, dalbavancin exerts its bactericidal effect by disrupting cell wall biosynthesis.

Dalbavancin is derived from the natural product glycopeptides by amination of the peptide-carboxy group of amino acid 7 with 3 -(dimethylamino)- 1- propylamine. The introduction of this substituent increases the potency against staphylococci, particularly coagulase-negative staphylococci.

Dalbavancin is a mixture of five closely related active homologs or factors (A0, A1, B0, B1 and B2), all of which are active (bactericidal) against a number of Gram-positive bacteria. The homologs all share the same core structure but differ in the fatty acid side chain of the N- acylaminoglucuronic acid moiety (R1) and/or the presence of an additional methyl group (R2) on the terminal amino group (Figure 1, below). The B0 factor is the predominant component of the active material.

Figure 1: Structural formula and substitution patterns of Dalbavancin hydrochloride Homologs

Glycopeptides, particularly dalbavancin, are very unstable in aqueous solution due to the glycosidic linkage, the primary degradant of dalbavancin in aqueous solution is a non-homologous component referred to as Mannosyl Aglycone (MAG). The Mannosyl Aglycone (MAG) is the major degradant product of dalbavancin. dalbavancinThe probable reason for the formation of MAG is a hydrolytic mechanism involving a nucleophilic attack of water at an anomeric carbon of the glycone sugar which is preceded by protonation of the oxygen on the phenyl ring by either acid or water. It is majorly formed in acidic and heat conditions.

Dalbavancin is currently marketed under the tradename DALVANCE® in the United States and XYDALBA® in Europe. It is a lyophilized formulation in a glass vial as a sterile, lyophilized, preservative-free, and white to off-white to pale yellow solid. Each vial contains dalbavancin HCl equivalent to 500 mg of dalbavancin as the free base, lactose monohydrate (129 mg) and mannitol (129 mg) as an excipient. Sodium hydroxide or hydrochloric acid may be added to adjust the pH at the time of manufacture. The powder is to be reconstituted and further diluted in 5% Dextrose injection USP for IV infusion.

As per the Patient Leaflet information, DALVANCE®/ XYDALBA® is to be reconstituted either with 25 mL of water for injection USP or 5% Dextrose injection USP. Further, this solution is to be diluted into an intravenous bag containing 5% Dextrose injection USP to render the final concentration of 1 mg/mL to 5 mg/mL of dalbavancin. The reconstitution of lyophilized vials can take nearly 5 min to get the clear colorless to yellow solution (Refer: xydalba-epar-product-information_en). Moreover, during reconstitution, the lyophilized formulation tends to form air bubbles in reconstituted solution. These further warrants necessary precautions for dilution and additional examination of IV infusion bag for foam or air bubbles.

MAG is the result of the hydrolysis of the glycosidic linkage of dalbavancin, resulting in a less bactericidal component which lacks the acylglucoronamine moiety. To minimize such degradation, the marketed product is sold in the US as a powder in a vial for reconstitution. It comprises of hydrochloride salt of dalbavancin as a lyophilized powder (500 mg of free base), lactose monohydrate (129 mg) and mannitol (129 mg). As per the Patient leaflet information, instructions have been provided to reconstitute the lyophilized product with either sterile water for injection, USP, or 5% dextrose injection USP, followed by dilution only with 5% dextrose injection, USP to a final concentration of 1 mg/mL to 5 mg/mL. The labelling instructions depicts that reconstituted vials or diluted intravenous bags may be stored either refrigerated (2 to 8 °C) or at a controlled room temperature (20 to 25 °C) and the total time from reconstitution to dilution and further to the administration should not exceed 48 hours. The European XYDALBA® product is likewise a single use vial comprising dalbavancin, lactose monohydrate and mannitol for reconstitution in water and dilution in 5% Dextrose injection. The XYDALBA® label further indicates that the use of sodium chloride-containing solutions will cause precipitation and should not be used for reconstitution or dilution. Importantly, the XYDALBA® label clearly states that the chemical and physical in-use stability for both the reconstituted and diluted solutions has been demonstrated to be 48 hours at or below 25°C.

US Patent No. 8,143,212 and US Patent No. 7,115,564 discloses a lyophilized dalbavancin formulation includes mannitol and lactose monohydrate.

US Patent No. 7,119,061 B2 describes a freeze-dried dry powder formulation of dalbavancin and stabilizers having ratio 2:1 ratio wherein formulation contains no more than about 4% MAG by weight after about three months at 40° C storage.

WO 2023/211501 A1 describes the ready-to-administer heat stable aqueous formulation of dalbavancin comprising buffer, metal ions and/or cyclodextrins having improved stability profile. However, such formulations especially containing (2-Hydroxypropyl)-ß-cyclodextrin (HP-ß-CD) and Sulfo-butylether-ß-cyclodextrin (SBE-ß-CD) could be hazardous to the human being. All cyclodextrin family excipients have been proven to show nephrotoxicity when administered intravenously. Moreover, HP-ß-CD is more nephrotoxic than SBE-ß-CD. The formulations further contain some metal ions which could cause additional complications and toxicity issues during excretion of the same through kidney. The examples describe the use of HP-ß-CD at concentration of 55 mM to 110 mM which exceeds the Inactive Ingredients Database (IIG) limit provided by USFDA. Considering maximum daily dose of dalbavancin as 1500 mg, 20 mg/mL solution would contain 55 mM (6 gm) of HP-ß-CD, whereas IIG limit for the same is 1.33 gm for intravenous injection.

Further, it has been established that dalbavancin is unstable in aqueous solutions, hence currently available marketed formulation is in the lyophilized form.

Therefore, there remains an unmet need to develop stable ready-to-dilute dalbavancin composition which can be safely administered to the human beings, and which contains minimum excipients with a simple manufacturing process providing improved and sustained stability profile in the aqueous form.

Summary of the invention:
The present invention relates to a stable ready-to-dilute aqueous pharmaceutical composition for parenteral administration comprising dalbavancin or pharmaceutically acceptable salts thereof as an active pharmaceutical ingredient and pharmaceutically acceptable excipients. The present aqueous formulation is preservative free and exhibits good storage stability in aqueous form. An additional advantage of the present invention is that medical practitioner does not need to reconstitute the solution which is less cumbersome and provides more flexibility and easiness during emergency situations as compared to known existing lyophilized formulation.

In first aspect of the present invention, a stable ready-to-dilute aqueous pharmaceutical composition for intravenous administration comprising dalbavancin or a pharmaceutically acceptable salts thereof; at least one or more stabilizers, at least one or more tonicity agents and/or co-solvents, at least one or more solvents and at least an acidifying agents and/or alkaline agents sufficient to adjust the pH of the aqueous formulation composition.

In another aspect of the invention, a stable ready-to-dilute aqueous dalbavancin composition comprising one or more stabilizers, which is preferably sugar, one or more tonicity agents or co-solvents such as sugar alcohol, one or more solvents such as water or buffer and one or more acidifying agents and/or alkaline agents sufficient to adjust the pH of solution in the range of about 4.0 to 6.0.

In an example of the first aspect, dalbavancin is dalbavancin hydrochloride.

In an example of the first aspect, dalbavancin hydrochloride is present in an amount of about 50 mg/mL to 200 mg/mL.

In another example of the first aspect, stabilizers comprise but not limited to sugar.
In another example of the first aspect, stabilizers are sugar which comprises but not limited to mannitol, lactose monohydrate, sucrose, sorbitol, cellulose, trehalose, maltose, dextrose or mixture thereof.

In a preferred example of the first aspect, sugar selected from mannitol and/or lactose monohydrate.

In an example of the first aspect, stabilizers are present in a concentration of about 10 to 80 mg/mL, preferably 10 to 50 mg/mL.

In an example of the first aspect, tonicity agents and/or co-solvents which comprises but not limited to sodium chloride, potassium chloride, acetate buffer, benzyl alcohol, propylene glycol, polyethylene glycol, dimethylacetamide (DMA), N-methylpyrrolidone, dimethylsulfoxide (DMSO), sugar alcohol such as anhydrous glycerol (glycerin), glycerol monohydrate, glycerin derivatives, glycerin conjugated polyols and physical mixtures of glycerin and other polyols or mixtures thereof.

In another example of the first aspect, tonicity agent/co-solvent is anhydrous glycerol.

In an example of the first aspect, tonicity agents/co-solvents are present in a concentration of about 10 mg/mL (1% w/v) to 800 mg/mL (80% w/v).

In an example of the first aspect, tonicity agents and/or co-solvents are present in a concentration of about 10 to 80 mg/mL, preferably 10 to 50 mg/mL.

In another example of the first aspect, solvents comprise but not limited to water or pharmaceutically acceptable buffer.

In another example of the first aspect, a pharmaceutically acceptable buffer comprises but not limited to acetate buffer, phosphate buffer, citrate buffer, or a mixture thereof with a pH range of 3.5 to 7.5, preferably with a pH of 4.5.

In the preferred example of the first aspect, the buffer solution has a concentration in the range of about 1 to 100 mM, preferably 1 to 50 mM, more preferably with 20 mM.

In yet another example of the first aspect, tonicity agents/co-solvents to solvents ratio selected from about 10:90 v/v to 90:10 v/v, more preferably the ratio selected from 30:70, 40:60, 50:50 or 20:80.

In further example of the first aspect, the acidifying agents and/or alkaline agents comprises but not limited to hydrochloric acid, sodium hydroxide, or a buffer.

In an example of the first aspect of the invention, pH of the composition may optionally range from 1-7, more preferably 2-6, more preferably 3-5, more preferably 4-5, more preferably approximate to 4.5.

In further aspect of the invention, dalbavancin pharmaceutical composition is free of preservative.

In another aspect of invention, the aqueous formulation exhibits promising impurity profiles with good stability over the long term conditions.

Detailed description:
The present subject matter may be understood more readily by reference to the following detailed description, which forms a part of this disclosure. It is to be understood that this invention is not limited to the specific methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed invention.

Unless otherwise defined herein, scientific and technical terms used in connection with the present application shall have the meanings that are commonly understood by those of ordinary skill in the art. Further, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular.
As used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise.

As used herein, the term “about” means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors. Ranges may be expressed herein as from “about” one particular value, and/or to “about” another particular value. As used herein, the term “about” means ±5%, ±10%, or ±20% of the value being modified.

“Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

The term "stable formulation" or “stabilized formulation” refers to any preparation of dalbavancin having sufficient physical and chemical stability to allow storage at a convenient temperature, for a reasonable period of time.

The term "stability", "chemical stability" or "stable" means that the product, composition or formulation exhibits an acceptable amount of API being present, or not more than a certain amount of API has degraded after a certain period of time. Accordingly, in a stable product, solution or formulation, unacceptable degradation of the active agent is avoided.

Stability can be presented as the purity or assay of dalbavancin in a composition according to the disclosure. If the composition initially contains dalbavancin of a certain purity or assay, the stability of the composition will be reflected by a decrease in the same in the product, formulation or composition over time, where a stable composition would contain the dalbavancin of a specified assay after a predetermined time period. For example, the formation of MAG is reduced in a stable product.

Accordingly, "stability" may also be defined by the amount of total or individual impurities generated after a certain period of time. The amount of impurities being present may be expressed as a percentage, for example as a peak-area percentage of a HPLC chromatogram or calculated according to standard solution.

The formulations of dalbavancin of the present disclosure can be for intravenous or parenteral administration. A ready-to-dilute formulation is a sterile, liquid injectable formulation not requiring reconstitution before use such that the formulation can be further diluted if present as a concentrated solution. The ready-to-dilute liquid formulations can be stored in a pharmaceutically suitable container, for example, a glass vial, ampoule, bottle, or syringe or plastic intravenous bag.

As used herein, the term "ready-to-dilute" refers to a formulation of dalbavancin or its pharmaceutically acceptable salts thereof which can be directly diluted with an infusion media (e.g., dextrose solution, water for injection, suitable non-aqueous solvents or any other infusion medium) and then administered to a patient. For example, a ready-to-dilute formulation can be stored to the container such as a vial, syringe or injector and can be further diluted to the required concentration and transferred to a final administration device such as a syringe or infusion bag for administration to a patient.

The present invention is directed to the stable aqueous formulation for intravenous administration that include dalbavancin, or a pharmaceutically acceptable salt thereof, at least one or more stabilizer, at least one or more tonicity agent and/or co-solvents, at least one or more solvent and at least one or more acidifying agent and/or alkaline agent sufficient to adjust the pH of the composition. The aqueous dalbavancin formulations of the current disclosure demonstrate the improved stability in aqueous form.

In the first embodiment of the present invention, a stable ready-to-dilute aqueous dalbavancin composition comprising one or more stabilizers, which is preferably sugar, one or more tonicity agents or co-solvents such as sugar alcohol, one or more solvents such as water or buffer and one or more acidifying agents and/or alkaline agents sufficient to adjust the pH of solution in the range of about 4.0 to 6.0.

In a preferred embodiment of the invention, dalbavancin is present in its pharmaceutically acceptable salts. The pharmaceutically acceptable salts preferably dalbavancin hydrochloride.

In one of the embodiments of the present invention, the dalbavancin hydrochloride is present in an amount of between about 20 mg/mL to about 200 mg/mL, preferably 50 mg/mL to 200 mg/mL.

In one of the embodiments, stabilizers comprise but not limited to sugar.

In one of the embodiments, stabilizers are sugars which comprises but not limited to mannitol, lactose monohydrate, sucrose, sorbitol, cellulose, trehalose, maltose, dextrose or mixture thereof.

In one of the preferred embodiments, sugar selected from mannitol and/or lactose monohydrate.

In one of the embodiments, stabilizers are present in a concentration of about 10 to 80 mg/mL, preferably 10 to 50 mg/mL.

In one of the embodiments, the tonicity agents/co-solvents comprise but not limited to sodium chloride, potassium chloride, acetate buffer, benzyl alcohol, propylene glycol, polyethylene glycol, dimethylacetamide (DMA), N-methylpyrrolidone, dimethylsulfoxide (DMSO), sugar alcohol such as anhydrous glycerol (glycerin), glycerol monohydrate, glycerin derivatives, glycerin conjugated polyols and physical mixtures of glycerin and other polyols or mixtures thereof.

In one of the preferred embodiments, tonicity agent/ co-solvent is anhydrous glycerol.

In an example of the first aspect, tonicity agents/co-solvents are present in a concentration of about 10 mg/mL (1% w/v) to 800 mg/mL (80% w/v).

In another embodiment, the tonicity agents/co-solvents are present in a concentration of about 10 to 80 mg/mL, preferably 10 to 50 mg/mL.

In one of the embodiments, solvent comprises but not limited to pharmaceutically acceptable buffer, water, isopropyl alcohol, benzyl alcohol, propylene glycol, polyethylene, glycolin or mixtures thereof.

In the preferred embodiment, a pharmaceutically acceptable buffer comprises but not limited to an acetate buffer, phosphate buffer, citrate buffer or mixture thereof with pH range of 3.5 to 7.5, more preferably with pH of 4.5.

In the preferred embodiment, the buffer has a concentration in the range of about 1 to 100 mM, preferably 1 to 50 mM, more preferably with 20 mM.

In yet another example of the first aspect, tonicity agents/co-solvents to solvents ratio selected from about 10:90 v/v to 90:10 v/v, more preferably the ratio is selected from 30:70, 40:60, 50:50 or 20:80.

In another embodiment, the formulation can further comprise of one or more acidifying agents and/or alkaline agents, for example, an acid or a base. The acidifying agents and/or alkaline agents serve to aid in adjusting the pH of the aqueous formulation.

In preferred embodiment, the acidifying agents and/or alkaline agents comprise of but not limited to hydrochloric acid, sodium hydroxide or a buffer, preferably hydrochloric acid and/or sodium hydroxide. The concentration of the acidifying agents and/or alkaline agents can be any concentration suitable for adjusting the pH.
In one of the embodiments, pH of the composition may optionally range from 1-7, more preferably 2-6, more preferably 3-5, more preferably 4-5, more preferably approximate to 4.5.

In another embodiment, the formulation is in aqueous form.

In another embodiment of the invention, the formulation is in ready-to-dilute form.
In yet another embodiment, the route of administration is intravenous.

In further embodiment of the invention, dalbavancin pharmaceutical composition is free of preservatives.

In further embodiment of the invention, the aqueous formulation exhibits promising impurity profiles with good stability over the long term conditions.

In another embodiment of the invention, the compositions of the present invention are stable with respect to the degradation impurities such as commercially known impurities as Impurity 1 (MAG), Impurity 2 and Impurity 3.

Impurity 1 - (MAG) or ((3S,15R,18R,34R,35S,38S,48R,50aR)-5,31-dichloro-38-{[3-(dimethylamino) propyl] carbamoyl}-6,11,34,40,44,56-hexahydroxy-42-(a-D-mannopyranosyloxy)-15-(methylamino) -2,16,36,50,51,59 - hexaoxo-2,3,16,17,18,19,35,36,37,38,48,49,50,50a-tetradecahydro-1H,15H,34H-20,23: 30,33-dietheno-3,18:35,48-bis(iminomethano)-4,8:10,14:25,28:43,47-tetrametheno [1,14,6,22] dioxadiaza cyclooctacosino[4,5-m] [10,2,16] benzoxadiazacyclotetracosin)

Impurity 2- (2-deoxy-1-O-[(3S,15R,18R,34R,35S,38S,48R,50aR)-5,31-dichloro-38-{[3-(dimethylamino) propyl]carbamoyl}-6,11,34,40,44-pentahydroxy-42-(a-D-mannopyranosyloxy)-15-(methylamino)-2,16, 36,50,51,59-hexaoxo-2,3,16,17,18,19,35,36,37,38,48,49,50,50a-tetradecahydro-1H,15H,34H-20,23:30,33 -dietheno-3,18:35,48-bis(iminomethano)-4,8:10,14:25,28:43,47-tetrametheno[1,14,6,22]dioxadiazacyclo octacosino[4,5-m][10,2,16]benzoxadiazacyclotetracosin-56-yl]-2-[(10-methylundecanoyl)]-ß-D-glucopyranuronic acid)

Impurity 3 - (2-deoxy-1-O-[(3S,15R,18R,34R,35S,38S,48R,50a R)-5,31-dichloro-38-{[3-dimethyl amino)propyl] carbamoyl}-6,11,34,40,44-hexahydroxy-15-(methylamino)-2,16,36,50,51,59-hexaoxo-2,3,16,17,18,19,35,36, 37,38,48,49,50,50a-tetradecahydro-1H,15H,34H-20,23:30,33-dietheno-3,18:35,48-bis(iminomethano)-4,8:10,14:25,28:43,47-tetrametheno[1,14,6,22] dioxadiazacycloo octacosino[4,5-m][10,2,16]benzoxa diaza cyclotetracosin-56-yl]-2-[(10-methylundecanoyl)amino]-ß-D-glucopyranuronic acid)

The liquid formulations of the present disclosure are stable or exhibit stability when stored, which includes formulation properties that may be affected by storage conditions, for example, active ingredient strength or concentration, impurities (e.g., different degradation impurities), visual appearance characteristics (e.g., color, clarity, cloudy, haze, precipitates, etc.) and Osmolality. Storage conditions that may affect stability can include, for example, storage temperature, humidity (e.g., relative) and storage time period.

In one or more embodiments of the invention, stability can be evaluated by the amount of total degradation impurities, visual appearance of the formulation, assay results of the prepared formulation, components of dalbavancin etc. Stable formulations are essentially clear solutions that are free or essentially free from visible signs of contamination from any foreign materials and/or particulate matter.
In further embodiments of the invention, osmolality level of diluted/admixture solution was investigated in 5% Dextrose injection. Osmolality indicates the concentration of all the particles dissolved in solution. Generally, for slow intravenous infusion osmolality range should be less than 900 mOsm/L for diluted solution.

In order to demonstrate the practice of the present invention, the following examples have been prepared and tested. The examples should not, however, be viewed as limiting the scope of the invention. The claims will serve to define the invention.

Examples
Preparation of various Dalbavancin formulations

The mixture of anhydrous glycerol and water for injection was prepared according to the ratios in table 1. Lactose monohydrate USP (25.8 mg) and mannitol USP (25.8 mg) were added to the above mixture. Dalbavancin hydrochloride was slowly added to the above mixture and a clear solution was prepared. The pH of the prepared solution was adjusted between 4.0 to 5.0 with target pH of 4.50 using 1.0 N sodium hydroxide / 1.0 N hydrochloric acid solution and final volume was make up to the 1 ml with the mixture of anhydrous glycerol and water for injection. pH of the final solution was checked.

Some formulations can also be prepared by following method with the same excipients and quantities mentioned in table 1 (Example 7).

Mannitol was added to about 40 to 50% of water for injection or acetate buffer pH 4.5 in manufacturing vessel under stirring. Clear solution was obtained. Lactose monohydrate was added to manufacturing vessel under stirring and clear solution was obtained. Glycerol or acetate buffer pH 4.5 was added to manufacturing vessel under stirring and clear solution was obtained. Dalbavancin hydrochloride was added to manufacturing vessel and stirred until clear solution was obtained. Adjusted the pH of the bulk solution within the range of 3.5 to 6.0 more preferably between 4.0 to 5.0. Make up the volume to the batch size with water for injection or acetate buffer pH 4.5. Filtered the solution through hydrophilic capsule filter. Aseptically, filled the filtered solution in vials (5 mL per vial for unit dose). Stoppered the vials and sealed. Stored the vials at 2°C to 8°C.

Table 1: Various Dalbavancin formulations
Compositions Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7
Dalbavancin hydrochloride (mg/ml) 100 50 100 100 100 100 100
Lactose monohydrate USP (mg/ml) 25.8
Mannitol USP (mg/ml) 25.8
Sodium hydroxide NF Q.S. to pH 4.0-5.0
Hydrochloric acid NF Q.S. to pH 4.0-5.0
Anhydrous glycerol: Water for injection (30:70 v/v) Q.S. to 1 mL Q.S. to 1 mL - - - - Q.S. to 1 mL
Anhydrous glycerol: Acetate buffer pH 4.5 (30:70 v/v) - - Q.S. to 1 mL - - - -
Anhydrous glycerol: Water for injection (40:60 v/v) - - - Q.S. to 1 mL - - -
Anhydrous glycerol: Water for injection (20:80 v/v) - - - - Q.S. to 1 mL - -
Anhydrous glycerol: Water for injection (50:50 v/v) - - - - - Q.S. to 1 mL -

HPLC method for degradation products analysis, assay and component distribution of dalbavancin in a dalbavancin formulation.

Instrument: HPLC equipped with UV/PDA Detector
Mobile phase A: Mixture of ammonium dihydrogen phosphate buffer and acetonitrile (95:5)
Mobile phase B: Mixture of ammonium dihydrogen phosphate buffer and acetonitrile (30:70)
Mode: Gradient
Detector: UV 210 nm
Column: C18,250 x 4.6 mm,3µm
Column temperature: 55ºC
Injection volume: 10µl
Samples are prepared by diluting with mixture of Water and Orthophosphoric acid in the ratio of (1000:2 v/v).

Degradation products analysis
HPLC method has been developed and validated for the estimation of known impurities and any individual unspecified impurities of Dalbavancin Injection, drug product. The method is specific to resolve all process and degradation impurities from main peak and other raw material (Placebo) present in drug product. The degradation product method by HPLC (HPLC equipped with UV/PDA detector) is capable to separate all known impurities and is stability indicating as well as validated.

Calculate % of each specified known impurity and unknown impurity by using following formula after discarding the peaks due to blank.

Aspl1 WStd Dspl P
% known Impurity = --------- x ---------- x ------------ x --------- x RF x Weight per mL (at 25°C)
AStd DStd Wspl L.C

Aspl1 WStd Dspl P
% Unknown Impurity = --------- x ---------- x ------------ x --------- x Weight per mL (at 25°C)
AStd DStd Wspl L.C

Where,
ASpl1 : Area of known/unknown impurity in sample preparation
AStd : Average area of dalbavancin B0 in standard preparation
WStd : Weight of dalbavancin HCl standard/API taken in mg in standard preparation
DStd : Dilution of standard preparation
Wspl : Weight of sample taken in gm
DSpl : Dilution of sample preparation.
P : Potency of dalbavancin HCl as a dalbavancin B0 absolute content (as is basis)
L.C : Label claim of dalbavancin in mg/mL (100mg/mL)
RF : Response Factor

Total Impurities: Sum of all Known Impurities + Sum of all Unknown impurities

Table 2 below sets forth the pH and degradation product analysis of dalbavancin formulation in anhydrous glycerol and water (30:70 v/v) prepared as described above (Example 1). The formulation was stored at 2-8°C and 25°C/60% RH.

Table 2: pH and degradation product analysis of 100 mg/mL dalbavancin formulation in anhydrous glycerol and water (30:70 v/v)
Parameters Initial (2-8°C) (25°C/60%RH)
1M 3M 5M 1M 2M 3M
Description CCS CCS CCS CCS CCS CCS CCS
pH 4.42 4.46 4.37 4.50 4.45 4.44 4.33
Degradation Products
Impurity1 (MAG) 0.15 0.22 0.38 0.59 0.55 1.24 1.92
Impurity 2 BQL BQL BQL BQL BQL BQL BQL
Impurity 3 BQL BQL BQL BQL BQL BQL BQL
Any individual unknown impurity BQL BQL BQL BQL BQL BQL BQL
Total Impurities 0.15 0.22 0.38 0.59 0.55 0.55 1.92
CCS: Clear Colorless Solution; BQL: Below Quantification Level; MAG: Mannosyl aglycone

As seen from Table 2, 100 mg/mL dalbavancin formulation in anhydrous glycerol and water (30:70 v/v) was found stable by appearance, pH and amount of total degradation impurities when stored for at least 5 months at 2-8°C and at least 3 months at 25°C/60% RH.

Osmolality of the above solution which is further diluted in dextrose injection USP was found to be 335 mOsmol/Kg.

Table 3 below sets forth the pH and degradation product analysis of dalbavancin formulation in anhydrous glycerol and water (30:70 v/v) prepared as described above (Example 2). The formulation was stored at 2-8°C and 25°C/60% RH.

Table 3: pH and degradation product analysis of 50 mg/mL dalbavancin formulation in anhydrous glycerol and water for injection (30:70 v/v)
Parameters Initial (2-8°C) (25°C/60%RH)
1 M 3 M 1 M 3 M
Description CCS CCS CCS CCS CCS
pH 4.57 4.55 4.56 4.59 4.58
Degradation Products
Impurity 1 (MAG) 0.6 0.42 0.6 1.65 4.09
Impurity 2 BQL BQL BQL BQL BQL
Impurity 3 BQL BQL BQL BQL BQL
Any individual unknown impurity BQL BQL BQL BQL BQL
Total Impurities 0.6 0.42 0.6 1.65 4.09
CCS: Clear Colorless Solution; BQL: Below Quantification Level; MAG: Mannosyl aglycone

As seen from Table 3, 50 mg/mL dalbavancin formulation in anhydrous glycerol and water (30:70 v/v) was found stable by appearance, pH and amount of total degradation impurities when stored for at least 3 months at 2-8°C and 25°C/60% RH.

Osmolality of the above solution which is further diluted in dextrose injection USP was found to be 335 mOsmol/Kg.

Table 4 below sets forth the pH and degradation product analysis of dalbavancin formulation in anhydrous glycerol and acetate buffer (30:70) prepared as described above (Example 3). The formulation was stored at 2-8°C and 25°C/60% RH.

Table 4: pH and degradation product analysis of 100 mg/mL dalbavancin formulation in anhydrous glycerol and acetate buffer (30:70 v/v)
Parameters Initial (2-8°C) (25°C/60%RH)
1 M 2 M 1 M 2 M
Description CCS CCS CCS CCS CCS
pH 4.32 4.44 4.44 4.42 4.45
Degradation Products
Impurity 1 (MAG) 0.57 0.54 0.71 1.83 4.27
Impurity 2 BQL BQL BQL BQL BQL
Impurity 3 BQL BQL BQL BQL BQL
Any individual unknown impurity BQL BQL BQL BQL BQL
Total Impurities 0.57 0.54 0.71 1.83 4.27
CCS: Clear Colorless Solution; BQL: Below Quantification Level; MAG: Mannosyl aglycone

As seen from Table 4, 100 mg/mL dalbavancin formulation in anhydrous glycerol and acetate buffer (30:70) was found stable by appearance, pH and amount of total degradation impurities when stored for at least 2 months at 2-8°C and 25°C/60%RH.

Osmolality of the above solution which is further diluted in dextrose injection USP was found to be 419 mOsmol/Kg.

Table 5 below sets forth the pH and degradation product analysis of dalbavancin formulation in anhydrous glycerol and water (40:60 v/v) prepared as described above (Example 4). The formulation was stored at 2-8°C and 25°C/60% RH.

Table 5: pH and degradation product analysis of 100 mg/mL dalbavancin formulation in anhydrous glycerol and water for injection (40:60 v/v)
Parameters Initial 3 M (2-8°C) 1 M (25°C/60%RH)
Description CCS CCS CCS
pH 4.68 4.62 4.62
Degradation Products
Impurity 1 (MAG) 0.88 1.21 2.94
Impurity 2 BQL ND BQL
Impurity 3 BQL BQL BQL
Any individual unknown impurity BQL BQL BQL
Total Impurities 0.88 1.21 2.94
CCS: Clear Colorless Solution; BQL: Below Quantification Level;
MAG: Mannosyl aglycone; ND: Not Detected

As seen from Table 5, 100 mg/mL dalbavancin formulation in anhydrous glycerol and water (40:60 v/v) was found stable by appearance, pH and amount of total degradation impurities when stored for at least 3 months at 2-8°C and at least 1 month at 25°C/60% RH.

Osmolality of the above solution which is further diluted in dextrose injection USP was found to be 548 mOsmol/Kg.

Table 6 below sets forth the pH and degradation product analysis of dalbavancin formulation in anhydrous glycerol and water (20:80 v/v) prepared as described above (Example 5). The formulation was stored at 2-8°C and 25°C/60% RH.

Table 6: pH and degradation product analysis of 100 mg/mL dalbavancin formulation in anhydrous glycerol and water for injection (20:80 v/v)
Parameters Initial 3 M (2-8 °C) 1 M (25°C/60%RH)
Description CCS CCS CCS
pH 4.65 4.64 4.58
Degradation Products
Impurity 1 (MAG) 0.84 1.1 2.55
Impurity 2 BQL BQL BQL
Impurity 3 BQL BQL BQL
Any individual unknown impurity BQL BQL BQL
Total Impurities 0.84 1.1 2.55
CCS: Clear Colorless Solution; BQL: Below Quantification Level; MAG: Mannosyl aglycone

As seen from Table 6, 100 mg/mL dalbavancin formulation in anhydrous glycerol and water (20:80 v/v) was found stable by appearance, pH and amount of total degradation impurities when stored for at least 3 months at 2-8°C and at least 1 month at 25°C/60%RH.Osmolality of the above solution which is further diluted in dextrose injection USP was found to be 395 mOsmol/Kg.

Table 7 below sets forth the pH and degradation product analysis of dalbavancin formulation in anhydrous glycerol and water (50:50) prepared as described above (Example 6). The formulation was stored at 2-8°C and 25°C/60% RH.

Table 7: pH and degradation product analysis of 100 mg/mL dalbavancin formulation in anhydrous glycerol and water for injection (50:50)
Parameters Initial 3 M (2-8°C) 1 M (25°C/60%RH)
Description CCS CCS CCS
pH 4.60 4.63 4.55
Degradation Products
Impurity 1 (MAG) 0.36 0.62 2.31
Impurity 2 BQL BQL BQL
Impurity 3 BQL BQL BQL
Any individual unknown impurity BQL BQL BQL
Total Impurities 0.36 0.62 2.31
CCS: Clear Colorless Solution; BQL: Below Quantification Level; MAG: Mannosyl aglycone

As seen from Table 7, 100 mg/mL dalbavancin formulation in anhydrous glycerol and water (50:50 v/v) was found stable by appearance, pH and amount of total degradation impurities when stored for at least 3 months at 2-8°C and at least 1 month at 25°C/60% RH.Osmolality of the above solution which is further diluted in dextrose injection USP was found to be 553 mOsmol/Kg.

Table 8 below sets forth the pH and degradation product analysis of dalbavancin formulation in anhydrous glycerol and water (30:70) prepared as described above (Example 7). The formulation was stored at 2-8°C and 25°C/60% RH.

Table 8: pH and degradation product analysis of 100 mg/mL dalbavancin formulation in anhydrous glycerol and water for injection (30:70)
Parameters Initial (2-8°C) (25°C/60%RH)
1M 3M 6M 1M 3M
Description CCS CCS CCS CCS CCS CCS
pH 4.42 4.46 4.37 4.50 4.45 4.44
Degradation Products
Impurity1 (MAG) 0.55 0.54 0.62 0.71 1.89 4.62
Impurity 2 BQL BQL BQL ND ND BQL
Impurity 3 BQL BQL BQL BQL BQL BQL
Any individual unknown impurity BQL BQL BQL BQL 0.11 0.16
Total Impurities 0.55 0.54 0.71 0.71 1.89 4.78
CCS: Clear Colorless Solution; BQL: Below Quantification Level;
MAG: Mannosyl aglycone; ND: Not Detected

As seen from Table 8, 100 mg/mL dalbavancin formulation in anhydrous glycerol and water (30:70 v/v) is found stable by appearance, pH and amount of total degradation impurities when stored for at least 6 months at 2-8°C.

Osmolality of the above solution which is further diluted in dextrose injection USP was found to be between 300 to 500 mOsmol/Kg.

Assay of dalbavancin formulation
The HPLC equipped with UV/PDA detector was used for performing dalbavancin drug product assay. The method is specific to resolve all dalbavancin components (A0, A1, B0, B1 and B2) from the impurities and other raw materials (placebo) present in the drug product. B0 being the major component, assay value is reported considering B0 as standard. Release and Regulatory specification with a limit of 92.0 to 105.0% and 90.0 to 110.0% of label claim is proposed for finished product respectively in order to ensure that drug product will comply with the stability limits of assay.

Assay was calculated by following formula:
Aspl WStd 200 P
mg / mL = --------- x ---------- x ----------- x -------- x Weight per mL (at 25°C)
AStd 50 Wspl 100
Where,
ASpl : Area of sum of dalbavancin A0, A1, B0, B1 and B2 peaks in sample preparation.
AStd : Average area of dalbavancin B0 peak in standard preparation-2 of 5 replicates
WStd : Weight of dalbavancin HCl standard-2 taken in mg.
Wspl : Weight of sample taken in gm
P : Potency of dalbavancin HCl as a dalbavancin B0 absolute content (as is basis)

Table 9: Assay of 100 mg/mL dalbavancin formulation in anhydrous glycerol and water (30:70 v/v)
Condition Initial (2-8°C) (25°C/60%RH)
1M 3M 6M 1M 3M 6M
Assay (%) 95.80 93.60 95.60 95.80 92.00 91.20 86.60

Data for the components of dalbavancin component distribution as (A0+A1), B0, (B1+B2)
Dalbavancin is a mixture of five closely related active homologs (A0, A1, B0, B1, and B2); the component B0 is the major component of dalbavancin . HPLC method is used for this test. The method is specific to resolve all dalbavancin components (A0, A1, B0, B1, and B2). Limits for the components are proposed based upon the development stability data.

Calculate the components by Area Normalization method,

Peak response of dalbavancin component
in sample chromatogram
Calculate the % Dalbavancin Component = -------------------------------------------------------- X 100
AT

Where,
AT: Sum of responses of all peaks in sample chromatogram

Table 10: Dalbavancin components distribution for 100 mg/mL dalbavancin formulation in anhydrous glycerol and water (30:70 v/v)
Components (%) Condition
Initial (2-8°C) (25°C/60%RH)
1 M 3 M 6 M 1 M 3 M 6 M
A0+A1 (%) 3.20 3.18 3.19 3.15 3.06 2.98 2.73
B0 90.14 90.17 89.77 89.68 87.89 83.18 76.80
B1+B2 5.56 5.47 5.71 5.44 5.37 5.26 4.74

,CLAIMS:
1. A stable ready-to-dilute aqueous pharmaceutical composition for intravenous administration comprising dalbavancin or a pharmaceutically acceptable salt thereof, at least one stabilizer, at least one tonicity agent/co-solvent and pH adjusting agent/s.

2. The pharmaceutical composition of claim 01, wherein the dalbavancin is dalbavancin hydrochloride.

3. The composition of claim 1, wherein the stabilizers are selected from the group consisting of mannitol, lactose monohydrate, sucrose, sorbitol, cellulose, trehalose, maltose, dextrose or mixture thereof.

4. The composition of claim 1, wherein the tonicity agents/co-solvents are selected from the group consisting of sodium chloride, potassium chloride, acetate buffer, benzyl alcohol, propylene glycol, polyethylene glycol, dimethylacetamide (DMA), N-methylpyrrolidone, dimethylsulfoxide (DMSO), sugar alcohol such as anhydrous glycerol (glycerin), glycerol monohydrate, glycerin derivatives, glycerin conjugated polyols and physical mixtures of glycerin and other polyols or mixtures thereof.

5. The composition of claim 1, wherein the pH adjusting agents are selected from the group consisting of hydrochloric acid, sodium hydroxide, buffer, or mixture thereof.

6. The composition of claim 1, wherein the solvents are selected from the group consisting of water or a pharmaceutically acceptable buffer.

7. The composition of claim 1, wherein the tonicity agents/co-solvents and solvents are present in a ratio 10:90 v/v to 90:10 v/v.

8. The pharmaceutical composition of claim 1, wherein the process for the preparation of stable ready-to-dilute aqueous pharmaceutical composition comprises steps as follows: a) add stabilizers to about 40 to 50% of water for injection and stir to obtain clear solution b) add tonicity agents/co-solvents and stir to obtain clear solution c) add dalbavancin to the above solution and stir to obtain clear solution c) adjust the pH within the range of 4.0 to 5.0 and make up the final volume with water for injection.

9. The pharmaceutical composition of any of the proceeding claims, wherein the pharmaceutical composition contains not more than about 5 % of a MAG impurity after storage at about 2-8°C for at least 6 months.