Claims:1. Stable, pre-lyophilized pharmaceutical composition free from polysaccharide and disaccharide for parenteral administration, wherein said composition comprising;
i. Micafungin sodium;
ii. a pharmaceutically acceptable stabilizing agent selected from the group
consisting of a polyvinylpyrrolidone (Kollidon PF 12),Dextrose, Galactose and mixture thereof in an aqueous vehicle; and
iii. 0.1 N Sodium Hydroxide solution as alkalizing agent,
wherein, pH of said composition is in the range of 5.0 to 7.0.
2. The pre-lyophilized pharmaceutical composition according to claim 1, wherein Micafungin sodium is present in an amount of 1mg to 100 mg/vial.
3. The pre-lyophilized pharmaceutical composition according to claim 1 comprises an effective amount of stabilizing agent in the range of 100mg to 1000 mg.
4. The pre-lyophilized pharmaceutical composition according to claim 1, wherein the stabilizing agent is polyvinylpyrrolidone (Kollidon PF 12).
5. The pre-lyophilized pharmaceutical composition according to claim 1 comprises an effective amount of polyvinylpyrrolidone (Kollidon PF 12) in the range of 100mg to1000 mg as a stabilizing agent.
6. The pre-lyophilized pharmaceutical composition according to claim 1 comprises an effective amount of polyvinylpyrrolidone (Kollidon PF 12) in the range of 100mg to 500 mg as a stabilizing agent.
7. A method of increasing stability of Micafungin or a pharmaceutically acceptable salt in an aqueous solution, comprising a step of combining Micafungin or a pharmaceutically acceptable salt thereof with a stabilizing agent selected from the group consisting of a polyvinylpyrrolidone (Kollidon PF 12), Dextrose, Galactose or mixture thereof.
8. Stable freeze dried pharmaceutical composition for parenteral administration,
comprising;
i. Micafunginsodium in an amount of 1mg to 100 mg/vial;
ii. 100mg to 1000mg of polyvinylpyrrolidone(Kollidon PF-12) in aqueous vehicle as a stabilizing agent;
iii. 0.1 N Sodium Hydroxide solution as alkalizing agent; wherein pH of said composition is in the range of 5.0 to 7.0.
9. The freeze dried pharmaceutical composition for parenteral administration according to claim 8, wherein said composition comprising;
i. Micafungin sodium in an amount of 50 mg/vial;
ii. 200 mg of polyvinylpyrrolidone(Kollidon PF-12) in aqueous vehicle as a stabilizing agent;
iii. 0.1 N Sodium Hydroxide solution as alkalizing agent; wherein pH of said composition is in the range of 5.0 to 7.0.
10. The freeze dried pharmaceutical composition for parenteral administration according to claim 8, wherein said composition comprising;
i. Micafungin sodium in an amount of 100 mg/vial;
ii. 400 mg of polyvinylpyrrolidone(Kollidon PF-12) in aqueous vehicle as a stabilizing agent;
iii. 0.1 N Sodium Hydroxide solution as alkalizing agent; wherein, pH of said composition is in the range of 5.0 to 7.0.
11. A process for preparation of freeze dried pharmaceutical composition comprising a) providing pre-lyophilized composition consisting of Micafungin sodium dissolved in aqueous vehicle containing stabilizing agent and alkalizing agent and b) lyophilizing the composition to obtain freeze dried pharmaceutical composition.
12. The process according to claim 1, wherein, stabilizing agent is selected from the group consisting of a polyvinylpyrrolidone (Kollidon PF 12), Dextrose, Galactose or mixture thereof and the alkalizing agent is 0.1 N Sodium Hydroxide solution.
, Description:Field of invention:

The present invention relates to freeze dried, pharmaceutical formulation of Micafungin sodium free from polysaccharide and disaccharide along with a suitable stabilizing agent and alkalizing agent for parenteral administration. The pharmaceutical formulation provides sufficient stabilization of Micafungin sodium thus improving the shelf life during storage. The invention further relates to a process of preparation thereof.

Background of the invention:

Fungal infections are an important problem, particularly in immune compromised patients, resulting from AIDS infections, aggressive cancer treatment, the growing use of organ transplants, and other nosocomial situations. Advanced medical therapies have created a critical need for new safe fungicidal agents that can be used to treat disseminated infections. Systemic mycoses are not easily diagnosed, andthe patient has usually been infected for quite some time before symptoms appear. Thus, empiric therapy needs to begin immediately, but currently available treatments have problems with toxicity or resistance.

The clinically available drugs were limited to amphotericin B, azoles, and flucytosine, although voriconazole and caspofungin have since been marketed. However, these drugs have problems regarding antifungal spectra of activity, toxicity or resistance. Furthermore, the emergence of multi-azole-resistant strains of Candida is leading to many serious fungal infections. Much interest has been focused on developing safer and more effective antifungal agents.(Pure Appl. Chem., Vol. 79, No. 4, pp. 603–614, 2007.)

Recently, a new class of antifungals, the echinocandins, has been developed. These agents interfere with cell wall biosynthesis by non-competitive inhibition of 1, 3-d-glucan Synthase, an enzyme present in fungi but absent in mammalian cells (Walsh et al., 2000; Ernst, 2001). They are used to treat a variety of fungal infections, including invasive infections due to either Candida or Aspergillus. These antifungals have shown clinical efficacy and a more favorable adverse-event (AE) profile compared with those of conventional antifungal agents.
Micafungin sodium is a semi synthetic lipopeptide (echinocandin) synthesized by a chemical modification of a fermentation product of Coleophomaempetri F-11899. Micafungin inhibits the synthesis of 1, 3-beta-D-glucan, an integral component of the fungal cell wall. Chemically, Micafungin sodium is Pneumocandin A0,1-[(4R,5R)-4,5-dihydroxy-N2-[4-[5-[4-(pentyloxy)phenyl]-3-isoxazolyl]benzoyl]-L-ornithine]-4-[(4S)-4-hydroxy-4-[4-hydroxy-3-(sulfooxy)phenyl]-L-threonine]-, monosodium salt(Fig 1). Micafungin sodium is a light-sensitive, hygroscopic white powder that is freely soluble in water, isotonic sodium chloride solution, N,N-dimethylformamide and dimethylsulfoxide, slightly soluble in methyl alcohol, and practically insoluble in acetonitrile, ethyl alcohol (95%), acetone, diethyl ether and n-hexane(DailyMed).
The chemical structure of Micafungin sodium is:

Fig 1

Micafungin sodium is marketed as lyophilized product for intravenous infusion by Astellas Pharma US, Inc. under the trade name MYCAMINE ®. Micafungin sodium is indicated for the treatment of Candidemia, Acute Disseminated Candidiasis, Candida Peritonitis, Abscesses, Esophageal Candidiasis and Prophylaxis of Candida Infections in Patients Undergoing Hematopoietic Stem Cell Transplantation.

Currently available formulations in lyophilized vial contain lactose as stabilizing agent which does not provide desirable stability due to the sensitivity of Micafungin sodium against environmental stress.

Indian patent number 215552 disclose a stable pharmaceutical composition of Micafungin in lyophilized form comprising lactose as stabilizing agent.

Further, Micafungin Sodium is generally unstable to light, heat, humidity, acid, and the like, it is necessary to develop a pharmaceutical composition for stabilizing the compound and the salts thereof for parenteral administration.

In view of the instability of Micafungin sodium in preparing the lyophilized product for parenteral administration as mentioned above, the present inventors felt a need to provide a stable Micafungin sodium injectable formulation which is free from polysaccharide and disaccharide with good shelf life.

While screening for suitable agents for stabilizing the formulation, the inventors have unexpectedly found that stabilized pharmaceutical formulation of Micafungin can be prepared for parenteral administration, without employing polysaccharide and disaccharide.

Summary of the invention:

In accordance with above, in an aspect, the present invention provides pre-lyophilized pharmaceutical formulation comprising Micafungin or pharmaceutically acceptable salt thereof along with a suitable stabilizing agent in an aqueous vehicle, wherein, the formulation is free from polysaccharide and disaccharide. In a preferred aspect, pharmaceutically acceptable salt of Micafungin is Micafungin sodium.

The Micafungin sodium is stabilized by adding stabilizing agents selected from the group consisting of a polyvinylpyrrolidone (Kollidon PF 12), Dextrose, Galactose and mixture thereof in aqueous vehicle to obtain pre-lyophilized formulation.

In another aspect, the pre-lyophilized pharmaceutical formulation of Micafungin sodium and stabilizing agent is freeze dried and provided as a drug concentrate, suitable for parenteral administration.

According to the invention, the freeze dried formulation comprises an effective amount of stabilizer in the range of 100mg to 1000 mg.

The pH of the formulation is maintained in the range of 5 to 7 using alkalizing agent.

In another aspect, the present invention provides a method for stabilization of Micafungin sodium in an aqueous solution which comprises combining Micafungin sodium in an aqueous vehicle with a stabilizing agent selected from the group consisting of polyvinylpyrrolidone (Kollidon PF 12), Dextrose, Galactose and mixture thereof.

Detailed description of the invention:

The invention will now be described in detail in connection with certain preferred and optional embodiments, so that various aspects thereof may be fully understood and appreciated.

Micafungin Sodium is generally unstable to light, heat, humidity, acid, and the like, it is necessary to develop a pharmaceutical composition for stabilizing the compound and the salts thereof for parenteral administration.

However, it is observed by the current inventors that it is possible to provide stable pharmaceutically acceptable composition/formulation for parenteral administration or intravenous infusion comprising of Micafungin sodium as the active using a suitable stabilizer and maintaining appropriate pH of the formulation.

In an embodiment, the present invention provides pre-lyophilized pharmaceutical composition comprising Micafungin sodium; a pharmaceutically acceptable stabilizing agent selected from the group consisting of a polyvinylpyrrolidone (Kollidon PF 12), Dextrose, Galactose and mixture thereof in an aqueous vehicle and alkalizing agent, wherein, pH of said composition is in the range of 5.0 to 7.0 and wherein, the pre-lyophilized composition is devoid of polysaccharide and disaccharide. The aqueous vehicle according to the invention is water for injection.

Micafungin sodium is present in the composition in an amount ranging from 1mg to 100 mg/vial; more preferably 50mg/vial and 100mg/vial.

Micafungin sodium is stabilized using a suitable stabilizing agent where Micafungin sodium can be maintained in a dissolved state in the aqueous solution thereby preventing crystallization or crystalline growth of Micafungin sodium. The stabilizing agent is selected from the group consisting of a polyvinylpyrrolidone (Kollidon PF 12), Dextrose, Galactose and mixture thereof. In one preferred embodiment, the stabilizing agent is polyvinylpyrrolidone (Kollidon PF 12).

In a preferred embodiment, the pre-lyophilized pharmaceutical composition comprises Micafungin sodium in an amount ranging from 1mg to 100 mg/vial; an effective amount of polyvinylpyrrolidone (Kollidon PF 12) in the range of 100mg to 1000 mg as a stabilizing agent in aqueous vehicle and 0.1 N Sodium Hydroxide solution as alkalizing agent for pH adjustment. The pre-lyophilized composition thus provided in aqueous vehicle is filtered to remove particulate matter, filled into vials and subjected to freeze drying cycle to obtain freeze dried composition.

In another embodiment, the present invention provides stable, freeze dried, pharmaceutical composition for parenteral administration, which is free from polysaccharide and disaccharide, comprising;
a) Micafungin sodium in an amount of 1 to 100mg/vial;
b) a pharmaceutically acceptable stabilizing agent selected from the group
consisting of a polyvinylpyrrolidone (Kollidon PF 12),Dextrose, Galactose and mixture thereof, and
c) alkalizing agent, wherein, pH of said composition is in the range of 5.0 to 7.0

The stabilizing agent is preferably polyvinylpyrrolidone (Kollidon PF 12), used in an amount of 100 to 1000mg.

In one preferred embodiment, the stable freeze dried pharmaceutical composition for parenteral administration, comprising;
i. Micafunginsodium in an amount of 50 mg/vial;
ii. 200mg of Kollidon PF-12 in aqueous vehicle as a stabilizing agent;
iii. 0.1 N Sodium Hydroxide solution as alkalizing agent; wherein pH of said composition is in the range of 5.0 to 7.0.
In another preferred embodiment, the stable freeze dried pharmaceutical composition for parenteral administration comprising;
i. Micafungin sodium in an amount of 100 mg/vial;
ii. 400 mg of Kollidon PF-12 in aqueous vehicle as a stabilizing agent;
iii. 0.1 N Sodium Hydroxide solution as alkalizing agent; wherein, pH of said
composition is in the range of 5.0 to 7.0.

According to another embodiment, the invention provides freeze drying process which involves cooling of pre-lyophilized pharmaceutical composition at suitable temperature not less than -50°C, raising temperature to 0°C at suitable pressure of 150 mtorr to 100 mtorr in 30 hours, then at 75 mtorr, further raising temperature to +15°C in 20 hrs, to obtain freeze-dried composition.

Such composition after freeze drying is chemically and physically stable over an extended period of time and is suitable for intended pharmaceutical use after reconstitution with suitable vehicle/diluents such as water for injection, sodium chloride injection or 5% dextrose injection.

The freeze dried Micafungin sodium provided in accordance with the invention when reconstituted with 5 ml of suitable vehicle contains final drug concentrate of 10 mg/ml.

In another embodiment, the invention provides process for preparation of freeze dried pharmaceutical composition of the invention which comprises a) providing pre-lyophilized composition consisting of Micafungin sodium dissolved in aqueous vehicle containing stabilizing agent and alkalizing agent and b) lyophilizing the composition to obtain freeze dried pharmaceutical composition. The freeze dried composition comprising Micafungin sodium may be diluted with suitable diluents before administration as IV injection. The final concentration of solution may be reduced to further desired level using 5% Dextrose infusion prior to administration to a patient.

The pharmaceutical compositions of the present invention are administered to a patient according to a dosing regimen. It should be understood that the specific dosing regimen for any particular patient will depend on a variety of factors, including age, body weight, general health, sex, diet, time of administration, specific disease being treated, and the severity of the condition among other factors and the judgment of the treating physician.

Other features and embodiments of the invention will become apparent by the following examples which are given for illustration of the invention rather than limiting its intended scope. Various changes and modifications to the disclosed embodiments will be apparent to those skilled in the art.

Experimental:
Two different trials were conducted and tested before narrowing down to the present formulation. These trials are discussed in brief below to emphasize the inventiveness of the current invention.

Example: 1
1.0 gm Micafungin sodium (active) was added to an aqueous solution containing 4 gm of Lactose and stirred for some time. Then added 7.6 mg anhydrous Citric acid and stirred for some time to get clear solution. Adjusted the pH of the solution to about 5.5 with 0.1 N Sodium Hydroxide solution and cooled down the solution below 20°C. Filtered the solution and the resulting solution was loaded into 20 vials (10 ml vial) with each containing 2.5 ml solution. The solution in each vial was lyophilized using freeze dryer according to conventional method, thereby obtaining the lyophilized compositions each comprising 50mg of Micafungin sodium. The resulting lyophilized preparation was stored at 40° C, and the residue of Micafungin was tested after 3 months and the results are provided in below table.

Period Assay (%) pH Single impurity (%) Total impurity (%) Storage temp. Color
Initial Bulk solution 99.35 5.50 0.39 0.55 - Clear colourless solution
Lyophilized 99.32 5.49 0.41 0.57 - White lyophilized cake
After 3 months 95.11 - 1.98 4.93 40°C Off-white lyophilized cake

Example: 2
1.0 gm Micafungin sodium (active) was added to an aqueous solution containing 4 gm of polyvinylpyrrolidone (Kollidon PF-12) and stirred for some time to get clear solution. Adjusted pH with 0.1 N Sodium Hydroxide solution to about 5.4. Filtered the solution and the resulting solution was loaded into 20 vials (10 ml vial) with each containing 2.5 ml solution. The solution in each vial was lyophilized using freeze dryer according to conventional method, thereby obtaining the lyophilized compositions each comprising 50 mg of Micafungin sodium. The resulting lyophilized preparation was stored at 2-8°C, 25°C and 40°C, and the residue of Micafungin was tested upto 3 months and the results are provided in below table.

Period Assay (%) pH Single impurity (%) Total impurity (%) Storage temp. Color
Bulk solution
99.76 5.40 0.32 0.53 - Clear colourless solution
Lyophilized
(Initial) 99.67 5.44 0.34 0.51 - White lyophilized cake
After 3 months 99.56 5.41 0.37 0.55 2-8°C White lyophilized cake
98.74 5.43 0.68 1.12 25°C White lyophilized cake
96.28 5.42 1.52 3.86 40°C White lyophilized cake
Industrial Advantages:
1. The freeze dried pharmaceutical composition comprising Micafungin sodium which is free from polysaccharide and disaccharide is provided herewith without compromising the stability of drug and its solution before Lyophilisation, has a pH between 5.0 to 7.0.
2. The formulation is stable for the entire period of the shelf life.
3. The stability of the freeze dried composition is more stable than the prior art formulation.