Claims:
1. A stable freeze-dried pharmaceutical composition for parenteral administration comprising,
a) Isavuconazonium Sulfate in an amount equivalent to 1mg to 200 mg Isavuconazole/vial;
b) Sodium Chloride as stabilizing agent in an amount of 10mg to 40mg/ vial;
c) Polysorbate 80 in an amount of 10mg to 150mg/ vial to prevent the formation of visible particulates after reconstitution of Lyophilized composition ; and
d) dilute Sulfuric acid for adjusting the pH of bulk composition between 1.3-2.3.

2. The stable freeze-dried pharmaceutical composition as claimed in claim 1, wherein the composition comprises,
a) Isavuconazonium Sulfate equivalent to Isavuconazole 200 mg;
b) Sodium chloride present in an amount of 10 mg to 40 mg and
c) Polysorbate 80 in an amount of 10mg to 150mg per vial.

3. The stable freeze-dried pharmaceutical composition as claimed in claim 1, wherein the composition comprises,
a) Isavuconazonium Sulfate equivalent to isavuconazole 200 mg;
b) Sodium chloride present in an amount of 18 mg; and
c) Polysorbate 80 present in an amount of 100 mg per vial

4. A process for the manufacture of a stable freeze dried pharmaceutical composition as claimed in claim 1, wherein, the process comprising the following steps:
a) Preparing an aqueous solution of Sodium Chloride and Polysorbate 80 in water for injection;
b) Cooling the solution between temperature of 2°C to 8°C and maintaining the temperature throughout the manufacturing under nitrogen purging;
c) Dissolving the Isavuconazonium Sulfate in the Solution obtained in step (b);
d) adjusting the pH of the Solution prepared in step (c) to between 1.3 to 2.3 with Dilute Sulfuric acid solution and make up volume to batch size with water for injection;
e) filtering the solution obtained in step (d) from 0.22 micron filter and filling into the vials;
f) freezing the Solution filled in vials obtained in step (e) and
g) freeze drying the frozen solution filled in vials obtained in step (f).

5. The process as claimed in claim 4, wherein the freeze drying process comprises the following steps:
a) freezing the solution of Isavuconazonium Sulfate filled in vials at a temperature below -35°C and maintaining said temperature for at least 4 hours;
b) primary drying of the frozen solution of step (a) under vacuum from 50 mtorr to 100 mtorr and at a temperature between -30 and 15°C, and maintaining said conditions for at least 45 hours; and
c) secondary drying of the primary dried frozen Solution of step (b) under vacuum from 10 mtorr to 50 mtorr and at a temperature between 15°C and 30°C, and maintaining said conditions for at least 9 hours, to achieve the freeze dried composition with water content not more than 2.0%.

6. A process for increasing the stability and preventing the formation of visible particulates after reconstitution of freeze-dried pharmaceutical composition of Isavuconazole in an aqueous solution as claimed in any one of the preceding claims, comprising a step of combining Isavuconazonium Sulfate with Sodium chloride and Polysorbate 80 in aqueous medium and maintaining the bulk solution within pH range of 1.3 to 2.3.
, Description:Technical Field of the Invention:
The present invention relates to stable freeze dried pharmaceutical compositions comprising Isavuconazonium sulfate along with suitable stabilizing agents for parenteral administration. These freeze dried compositions have advantageous properties when reconstituted for injection. The invention further relates to a process for preparation of said composition.

Background of the Invention:
Coinciding with the continually increasing population of immune-compromised patients worldwide, the incidence of invasive fungal infections has grown over the past 4 decades. Unfortunately, infections caused by both yeasts such as Candida and molds such as Aspergillus or Mucorales remain associated with unacceptably high morbidity and mortality. In addition, the available antifungals with proven efficacy in the treatment of these infections remain severely limited. Although previously available second-generation triazole antifungals have significantly expanded the spectrum of the triazole antifungal class, these agents are laden with shortcomings in their safety profiles as well as formulation and pharmacokinetic challenges. Isavuconazole, administered as the prodrug isavuconazonium, is the latest second-generation triazole antifungal to receive U.S. Food and Drug Administration approval. Approved for the treatment of both invasive aspergillosis and invasive mucormycosis, and currently under investigation for the treatment of candidemia and invasive candidiasis, isavuconazole may have therapeutic advantages over its predecessors. With clinically relevant antifungal potency against a broad range of yeasts, dimorphic fungi, and molds, isavuconazole has a spectrum of activity reminiscent of the polyene amphotericin B. Moreover, clinical experience thus far has revealed isavuconazole to be associated with fewer toxicities than voriconazole, even when administered without therapeutic drug monitoring. These characteristics, in an agent available in both a highly bioavailable oral and a ß-cyclodextrin-free intravenous formulation, will likely make isavuconazole a welcome addition to the triazole class of antifungals. (Pharmacotherapy, 2015 Nov;35(11):1037-51. doi: 10.1002/phar.1652. Epub 2015 Nov 2. Jeffrey M Rybak et al.).
Isavuconazonium sulfate, which is the prodrug of isavuconazole, an azole antifungal drug. Isavuconazonium sulfate drug substance is an amorphous, white to yellowish-white powder. The chemical name of isavuconazonium sulfate is glycine, N-methyl-, [2-[[[1-[1-[(2R,3R)-3-[4-(4-cyanophenyl)-2-thiazolyl]-2-(2,5-difluorophenyl)-2-hydroxybutyl]-4H-1,2,4 triazolium-4-yl]ethoxy]carbonyl]methylamino]-3-pyridinyl]methyl ester, sulfate (1:1). The empirical formula is C35 H35 F2 N8 O5 S·HSO4 , the molecular weight is 814.84 and the structural formula is:

Lyophilized pharmaceutical product when reconstituted with carrier solution for parenteral application may lead to the formation of visible and subvisible particle in the solution. Solution for parenteral administration, including solution constituted from sterile solids should be essentially free from visible and subvisible particles that can be observed on visual inspection and it is also desirable to have a low number of Subvisible particles for patient safety. IP (Indian Pharmacopeia 2018) describes physical tests performed for the purpose of enumerating Subvisible extraneous particles within Specific size ranges and also defines particulate matters limits for the test being applied for large Volume Injections for Single-dose infusion and Small-Volume injections.
The particulate matter present in intravenous infusion can result in severe consequences, such as vein irritation, anaphylactic shock, phlebitis, pulmonary emboli, pulmonary granulomas, immune system dysfunction, pulmonary dysfunction, infarction, and death, based upon the number of particles, particle size/ shape, patient population, particle composition and route of administration. The size of particulate matter is an important factor behind health risk to patients. (Journal of Pharmacovigilance, J Pharmacovigil 2014, 3:1,DOI: 10.4172/2329-6887.1000e128, Tawde, et al).

CRESEMBA (Isavuconazonium sulfate) for injection is available for intravenous administration. CRESEMBA for injection is a white to yellow sterile lyophilized powder containing 372 mg isavuconazonium sulfate, equivalent to 200 mg isavuconazole, per vial. Inactive ingredients included in each vial are 96 mg mannitol and sulfuric acid for pH adjustment.

Isavuconazoniuim sulfate is marketed as lyophilized product for intravenous infusion by Astellas Pharma US, Inc. under the trade name CRESEMBA®. Isavuconazonium sulfate is indicated for patients 18 years of age and older for the treatment of invasive aspergillosis and invasive mucormycosis.

Currently available formulations of Isavuconazonium sulfate is in lyophilized vial containing 96 mg mannitol and sulfuric acid for pH adjustment. CRESEMBA for Injection needs to be stored at 2°C to 8°C;

Dilution and Preparation Instructions for the Injection Formulation mentioned in innovator PI as follows:
“Remove 5 mL of the reconstituted solution from the vial and add it to an infusion bag containing 250 mL (approximately 1.5 mg isavuconazonium sulfate per mL) of compatible diluent. The diluted solution may show visible translucent to white particulates of isavuconazole (which will be removed by in-line filtration). Use gentle mixing or roll bag to minimize the formation of particulates. Avoid unnecessary vibration or vigorous shaking of the solution. Apply in-line filter with a microporous membrane pore size of 0.2 to 1.2 micron and in-line filter reminder sticker to the infusion bag”.

As is evident from the above, the marketed product ‘CRESEMBA’ has severe limitations in reconstituting for an injectable preparation as it requires an infusion bag and an in-line filter with a microporous membrane pore size of 0.2 to 1.2 micron and in-line filter reminder sticker.

The in-line IV filters are commonly used for the prevention of air from reaching the systemic circulation and also to filter fluid contaminants such as undissolved drug particles; precipitates; bacteria; endotoxins; fragments of glass, plastic, or rubber; and large lipids. However, the negative aspects of in-line IV filters include reduction of infusion flow rates secondary to filter clogging; added costs and environmental issues in disposing these medical waste after use.

Further, Isavuconazonium Sulfate generally forms visible translucent to white particulates of isavuconazole when reconstituted with 250 ml 0.9% w/v sodium chloride injection. Hence, it is necessary to develop a pharmaceutical composition which is free from visible translucent to white particulates for parenteral administration.
In view of the nature of Isavuconazonium Sulfate that forms particles of Isavuconazole during reconstitution and the resultant challenges in preparing the lyophilized product for parenteral administration as mentioned above, the present inventors felt a need to develop a stable Isavuconazole injectable composition without compromising stability using a suitable excipient(s).

The present inventors felt a further need for developing stable pharmaceutical composition comprising of Isavuconazonium sulphate which is free from visible translucent to white particulates of isavuconazole, and thus avoids the need of in-line filter with a microporous membrane pore size of 0.2 to 1.2 micron and in-line filter reminder sticker to the infusion bag.
Moreover, it would be desirable to provide compositions having a good stability so that the reconstituted solution will be clear and thus the additional costs involved in, in-line filter with a microporous membrane and in-line filter reminder sticker to the infusion bag, can be avoided.

In light of the above, it is therefore the object of the present invention to provide a stable, freeze-dried pharmaceutical composition, which prevents the formation of visible particulates, for parenteral administration comprising Isavuconazole or its pharmaceutical salt as an active ingredient using a suitable excipient and acidifying agent which lowers the degradation of active and improves the shelf life of the composition by equally reducing the impurities formation.

Summary of the Invention:
In pursuit of the above objectives, the present inventors have unexpectedly noticed that, it is possible to provide a pharmaceutical composition which prevents the formation of visible particulates during reconstitution.

Accordingly, the present invention provides a stable, freeze dried pharmaceutical composition comprising Isavuconazonium Sulfate along with a suitable excipient(s) and acidifying agent for parenteral administration.

In the present invention, Isavuconazonium Sulfate is stabilized by adding stabilizing agents especially, Sodium Chloride and Polysorbate 80 is added to prevent the formation of visible particulates after reconstitution of Lyophilized formulation.

In an aspect, the pharmaceutical composition of Isavuconazonium Sulfate and suitable excipients is freeze dried and is provided as a drug concentrate.

In another aspect, the present invention provides a method for stabilization of Isavuconazonium Sulfate in lyophilized form.

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.

The present invention discloses a stable, freeze-dried pharmaceutical composition for parenteral administration comprising Isavuconazonium Sulfate as an active ingredient along with Sodium Chloride as stabilizing agent and polysorbate 80 to prevent the formation of visible particulates after reconstitution of Lyophilized formulation and acidifying agent. The composition provides stabilization of Isavuconazonium sulfate with low degradation of the active ingredient thereby improving shelf life of the composition during storage and equally reducing the impurities formation.
Accordingly, in a preferred embodiment, the present invention provides a stable, freeze dried pharmaceutical composition for parenteral administration comprising;
i. Isavuconazonium Sulfate, and
ii. sodium chloride as stabilizing agent and polysorbate 80 to prevent the formation of visible particulates after reconstitution of Lyophilized formulation ,
Wherein the pH of said composition of the bulk solution is maintained within the range of 1.3 to 2.3 using acidifying agent before freeze drying.

Isavuconazonium Sulfate is present in the composition in an amount of 1 mg to 400 mg/vial; more preferably, 200mg/vial of Isavuconazole.

Isavuconazonium Sulfate is stabilized using a suitable stabilizing agent where Isavuconazole can be maintained in a dissolved state in the aqueous solution thereby preventing crystallization or crystalline growth of Isavuconazole or to prevent the formation of visible particulates after reconstitution of Lyophilized formulation. The stabilizing agent is Sodium Chloride and Polysorbate 80 acts to prevent the formation of visible particulates after reconstitution of Lyophilized formulation.

The composition of the present invention comprises Sodium chloride as stabilizing agent present in an amount of 10mg to 40 mg/ vial, more preferably, 10mg to 20mg/ vial.

The composition of the present invention comprises Polysorbate 80 to prevent the formation of visible particulates after reconstitution of Lyophilized formulation, present in an amount of 100mg to 400 mg/ vial, more preferably, 100mg to 200mg/ vial.

The pH of the composition is maintained within the range of 1.3 to 2.3 using acidifying agent, such as dilute Sulfuric acid solution.
In an embodiment, the present invention discloses a stable, freeze-dried pharmaceutical composition, for parenteral administration comprising;
a) Isavuconazonium Sulfate in an amount equivalent to 1 mg to 200 mg Isavuconazole /vial;
b) Sodium Chloride in an amount of 10mg to 40mg/ vial;
c) Polysorbate 80 present in an amount of 100mg to 400 mg/ vial to prevent the formation of visible particulates after reconstitution of Lyophilized formulation and
d) Acidifying agent such as dilute Sulfuric acid solution for adjusting the pH of in the range of 1.3 to 2.3.

In another embodiment, the present invention discloses a stable, freeze-dried pharmaceutical composition comprising;
a) Isavuconazonium Sulfate in an amount equivalent to 200mg Isavuconazole /vial;
b) Sodium Chloride in an amount of 18mg / vial;
c) Polysorbate 80 in amount of 100 mg/vial to prevent the formation of visible particulates after reconstitution of Lyophilized formulation and
d) Dilute Sulfuric acid solution for adjusting the pH in the range of 1.3 to 2.3.

The composition of the present invention after freeze drying is chemically and physically stable over an extended period of time and is suitable for intended pharmaceutical use after reconstitution with water for injection, 0.9% w/v sodium chloride injection or 5% w/v dextrose injection.

In another embodiment, the invention provides a process for the manufacture of a stable freeze dried pharmaceutical composition of Isavuconazonium Sulfate comprising the following steps:

a) Preparing an aqueous solution of Sodium Chloride and Polysorbate 80 in water for injection;
b) Cooling the solution between temperature of 2°C to 8°C and maintaining the temperature throughout the manufacturing under nitrogen purging;.
c) Dissolving the Isavuconazonium Sulfate in the Solution obtained in step (b);
d) adjusting the pH of the Solution prepared in step (c) to between 1.3 to 2.3 with Dilute Sulfuric acid solution and make up volume to batch size with water for injection;
e) filtering the solution obtained in step (d) from 0.22 micron filter and filling into the vials;
f) freezing the Solution filled in vials obtained in step (e) and
g) freeze drying the frozen solution filled in vials obtained in step (f).

The process of freeze drying comprises the following steps:
a) freezing the solution of Isavuconazonium Sulfate filled in vials at a temperature below -35°C and maintaining said temperature for at least 4 hours;
b) primary drying of the frozen solution of step (a) under vacuum from 50 mtorr to 100 mtorr and at a temperature between -30 and 15°C, and maintaining said conditions for at least 45 hours; and
c) secondary drying of the primary dried frozen Solution of step (b) under vacuum from 10 mtorr to 50 mtorr and at a temperature between 15°C and 30°C, and maintaining said conditions for at least 9 hours, to achieve the freeze dried compositions with water content not more than 2.0%.

The freeze dried isavuconazole when reconstituted with 5 ml of suitable vehicle contains final drug concentrate of 40 mg/ml.

The freeze dried drug 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 composition of the present invention is useful in the treatment of Invasive Aspergillosis and Invasive Mucormycosis.

In another embodiment, the invention provides a process for increasing the stability and preventing the formation of visible particulates after reconstitution of freeze-dried pharmaceutical composition of Isavuconazole in an aqueous solution which process comprises a step of combining Isavuconazonium Sulfate with Sodium chloride and Polysorbate 80 in aqueous medium and maintaining the bulk solution within pH range of 1.3 to 2.3.

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.

Industrial Advantages:
1. The pharmaceutical composition comprising Isavuconazonium Sulfate as active with Sodium chloride and polysorbate 80 improves the stability and solubilisation of drug in solution and Lyophilized form, has a pH between 1.3 to 2.3.
2. The composition is stable for the entire period of the shelf life.
3. The present freeze dried compositions of Isavuconazonium Sulfate avoids the need to use in-line filter with a microporous membrane pore size of 0.2 to 1.2 micron and in-line filter reminder sticker to the infusion bag, as it is table at room temperature (25°C) and further devoid of visible particulate matter and hence is cost-effective when compared to innovator’s CRESEMBA.

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:
Different trials were conducted using different Excipients and tested before arriving at the present composition.

Quantity/Vial in mg
Trial No 1 2 3 4 5
Isavuconazonium Sulfate eq.to.Isavuconazole 200 200 200 200 200
Mannitol 96 - - 96 -
Sodium Chloride - 18 - - 18
Polysorbate 80 - - 100 100 100
pH of bulk solution adjusted with Dilute Sulfuric acid solution 1.65 1.63 1.64 1.59 1.61
Assay of Lyophilized composition (Initial) 98.17 98.47 98.12 98.14 98.58
Total impurities (Initial) 1.85 1.64 1.94 1.96 1.48
Assay of Lyophilized composition (after 3 months kept at 25°C ) 96.63 97.19 96.19 96.18 97.50
Total impurities (after 3 months kept at 25°C ) 3.25 2.82 3.78 3.76 2.55
formation of visible particulates after reconstitution of Lyophilized formulation with 5 ml sterile water for injection and further diluted with 250 ml 0.9%sodium chloride injection or 5% Dextrose injection YES YES NO NO NO

Based on above trial experiments, the lyophilized compositions of Isavuconazonium Sulfate gives better stability with Sodium chloride and Polysorbate 80 (trial 5) when compared to sodium chloride (trail 2); polysorbate (trail 3); combination of polysorbate and mannitol (trail 4) and over the innovator’s compositions containing Mannitol (trial 1), at pH range 1.5 to 1.7 at bulk solution stage. Therefore, further experimental trials have been conducted with Sodium Chloride and Polysorbate 80 at different bulk solution pH level (i.e. 1.3 to 2.3, 2.3 to 3.3 and 3.3 to 4.3).
Surprisingly, it has been found that when Polysorbate 80 is included to the aqueous Solution of Isavuconazonium sulphate with Mannitol and dilute sulphuric acid, (trail 4), a lyophilisate can be obtained without Subvisible particles after reconstitution with a diluent compared to lyophilisates of the state of the art. This experiment establishes that the addition of Polysorbate 80 to the freeze dried compositions of Isavuconazonium sulphate and mannitol prevents the formation of particulate matter upon reconstitution.
The lyophilisate (trail 5) according to the invention is very stable with absence of any particulate matter and can be easily reconstituted with suitable solvents. The Isavuconazonium sulphate injection according to the invention has less than 150 subvisible particles of 10 micron per container.

The trials of Innovator formulation in comparison with present invention under different pH conditions are discussed in brief below to emphasize the inventiveness of the current invention and the analysis was carried out as per Standard and approved test Procedures.

Trial: 6 (Formulation prepared as per PIL (Patient Information Leaflet) of Cresemba)

Dissolved 1.920 gm of Mannitol in 64 ml Water for injection. 7.460 gm of Isavuconazonium Sulfate equivalent to 4.0 gm Isavuconazole free base was then added and dissolved. After the Active was added, the pH was adjusted to 1.3 to 2.3 using 1M Sulfuric acid solution, if required. The volume of the resulting solution was adjusted to 80 ml with additional water for injection and mixed well. The mixture was then filtered through a sterile 0.22 micron filter. Type 1 glass vials were then filled with 4.0 ml of the solution per vial. The solution in each vial was lyophilized using freeze dryer according to conventional method, thereby obtaining the lyophilized compositions of each vial comprising 200 mg of Isavuconazole. The resulting lyophilized preparation was stored at different storage temperatures at different time intervals and the residue of Isavuconazole was tested and the results are shown in below table.

Period Assay (%) pH Total impurities (%) Storage temp. Colour formation of visible particulates after reconstitution of Lyophilized formulation with 5 ml sterile water for injection and further diluted with 250 ml 0.9% sodium chloride injection or 5% Dextrose injection
Initial Bulk solution 98.23 1.37 1.81 2-8° C Clear, very light yellow colour solution -
Lyophilized
98.04 1.36 1.98 2-8° C Very Light yellow colour lyophilized cake
YES
After 3 months 96.65 1.41 3.33 25°C Light yellow colour lyophilized cake
YES

*for determination of pH - one lyophilized vial reconstituted with 5 ml water for Injection.

As is evident from the above trial 6, when the pH of the bulk solution is adjusted between 1.3 to 2.3; the composition exhibits more impurities after the 3 months and developed visible particulates after reconstitution of Lyophilized formulation with 5 ml sterile water for injection and further diluted with 250 ml 0.9%sodium chloride injection or 5% Dextrose injection at initial stage and after the 3months.

Trial: 7
Dissolved 0.360 gm of Sodium chloride and 2.0 gm of Polysorbate 80 in 64 ml Water for injection. Cooled the solution between temperature of 2°C to 8°C and maintained the temperature throughout the manufacturing under nitrogen purging. 7.460 gm of Isavuconazonium Sulfate equivalent to 4.0 gm Isavuconazole free base was then added and dissolved. After the Active was added, the pH was adjusted to 1.3 to 2.3 using 1M Sulfuric acid solution, if required. The volume of the resulting solution was adjusted to 80 ml with additional water for injection and mixed well. The mixture was then filtered through a sterile 0.22 micron filter. Type 1 glass vials were then filled with 4.0 ml of the solution per vial. The solution in each vial was lyophilized using freeze dryer according to the following process, thereby obtaining the lyophilized compositions of each vial comprising 200 mg of Isavuconazole.
The process of freeze drying comprises the following steps:
a) freezing the solution of Isavuconazonium Sulfate filled in vials at a temperature below -35°C and maintaining said temperature for at least 4 hours;
b) primary drying of the frozen solution of step (a) under vacuum from 50 mtorr to 100 mtorr and at a temperature between -30 and 15°C, and maintaining said conditions for at least 45 hours; and
c) secondary drying of the primary dried frozen Solution of step (b) under vacuum from 10 mtorr to 50 mtorr and at a temperature between 15°C and 30°C, and maintaining said conditions for at least 9 hours, to achieve the freeze dried compositions with water content not more than 2.0%.
The resulting lyophilized preparation was stored at different storage temperatures at different time intervals and the residue of Isavuconazole was tested for assay, stability, particulate matter and the results are described herein below table.

Period Assay (%) pH Total impurities (%) Storage temp. Colour formation of visible particulates after reconstitution of Lyophilized formulation with 5 ml sterile water for injection and further diluted with 250 ml 0.9%sodium chloride injection or 5% Dextrose injection
Initial Bulk solution 98.43 1.58 1.51 2-8° C Clear, very light yellow colour solution -
Lyophilized
98.39 1.49 1.58 2-8° C Very Light yellow colour lyophilized cake
NO
After 3 months 97.45 1.47 2.53 25°C Light yellow colour lyophilized cake
NO

*for determination of pH - one lyophilized vial reconstituted with 5 ml water for Injection.

As is evident from the above trial 7, when the pH of the bulk solution is adjusted between 1.3 to 2.3; the composition exhibits good stability and do not develop visible particulates after reconstitution of Lyophilized formulation with 5 ml sterile water for injection and further diluted with 250 ml 0.9% sodium chloride injection or 5% Dextrose injection at initial stage and after the 3months. Also, the lyophilized cake exhibits relatively less impurities even after 3 months at 25°C as shown in Trial 7.

Trial: 8
Dissolved 0.360 gm of Sodium chloride and 2.0 gm of Polysorbate 80 in 64 ml Water for injection. Cooled the solution between temperatures of 2°C to 8°C and maintained the temperature throughout the manufacturing under nitrogen purging. 7.460 gm of Isavuconazonium Sulfate equivalent to 4.0 gm Isavuconazole free base was then added and dissolved. After the Active was added, the pH was adjusted to 2.3 to 3.3 using 1M Sulfuric acid solution, if required. The volume of the resulting solution was adjusted to 80 ml with additional water for injection and mixed well. The mixture was then filtered through a sterile 0.22 micron filter. Type 1 glass vials were then filled with 4.0 ml of the solution per vial. The solution in each vial was lyophilized using freeze dryer according to following process, thereby obtaining the lyophilized compositions of each vial comprising 200 mg of Isavuconazole.
The process of freeze drying comprises the following steps:
a) freezing the solution of Isavuconazonium Sulfate filled in vials at a temperature below -35°C and maintaining said temperature for at least 4 hours;
b) primary drying of the frozen solution of step (a) under vacuum from 50 mtorr to 100 mtorr and at a temperature between -30 and 15°C, and maintaining said conditions for at least 45 hours; and
c) secondary drying of the primary dried frozen Solution of step (b) under vacuum from 10 mtorr to 50 mtorr and at a temperature between 15°C and 30°C, and maintaining said conditions for at least 9 hours, to achieve the freeze dried compositions with water content not more than 2.0%.
The resulting lyophilized preparation was stored at different storage temperatures at different time intervals and the assay of Isavuconazole, presence of particulate matter and impurities were tested and the results are described in below table.

Period Assay (%) pH Total impurities (%) Storage temp. Colour formation of visible particulates after reconstitution of Lyophilized formulation with 5 ml sterile water for injection and further diluted with 250 ml 0.9%sodium chloride injection or 5% Dextrose injection
Initial Bulk solution 97.85 2.78 2.11 2-8° C Clear, very light yellow colour solution -
Lyophilized
97.79 2.75 2.18 2-8° C Very Light yellow colour lyophilized cake
NO
After 3 months 96.59 2.77 3.39 25°C Light yellow colour lyophilized cake
NO

*for determination of pH - one lyophilized vial reconstituted with 5 ml water for Injection.

As is evident from the above trial 8, when the pH of the bulk solution is adjusted between 2.3 to 3.3; the composition exhibits more impurities after the 3months, although no particulate matter was observed.

Trial: 9
Dissolved 0.360 gm of Sodium chloride and 2.0 gm of Polysorbate 80 in 64 ml Water for injection. Cooled the solution between temperature of 2°C to 8°C and maintained the temperature throughout the manufacturing under nitrogen purging. 7.460 gm of Isavuconazonium Sulfate equivalent to 4.0 gm Isavuconazole free base was then added and dissolved. After the Active was added, the pH was adjusted to 3.3 to 4.3 using 1M Sulfuric acid solution, if required. The volume of the resulting solution was adjusted to 80 ml with additional water for injection and mixed well. The mixture was then filtered through a sterile 0.22 micron filter. Type 1 glass vials were then filled with 4.0 ml of the solution per vial. The solution in each vial was lyophilized using freeze dryer according to following process, thereby obtaining the lyophilized compositions of each vial comprising 200 mg of Isavuconazole.

The process of freeze drying comprises the following steps:
a) freezing the solution of Isavuconazonium Sulfate filled in vials at a temperature below -35°C and maintaining said temperature for at least 4 hours;
b) primary drying of the frozen solution of step (a) under vacuum from 50 mtorr to 100 mtorr and at a temperature between -30 and 15°C, and maintaining said conditions for at least 45 hours; and
c) secondary drying of the primary dried frozen Solution of step (b) under vacuum from 10 mtorr to 50 mtorr and at a temperature between 15°C and 30°C, and maintaining said conditions for at least 9 hours, to achieve the freeze dried compositions with water content not more than 2.0%.

The resulting lyophilized preparation was stored at different storage temperatures at different time intervals and the assay of Isavuconazole, presence of particulate matter and impurities were tested and the results are described in the below table.

Period Assay (%) pH Total impurities (%) Storage temp. Colour formation of visible particulates after reconstitution of Lyophilized formulation with 5 ml sterile water for injection and further diluted with 250 ml 0.9%sodium chloride injection or 5% Dextrose injection
Initial Bulk solution 97.55 3.88 2.47 2-8° C Clear, very light yellow colour solution -
Lyophilized
97.41 3.82 2.58 2-8° C Very Light yellow colour lyophilized cake
NO
After 3 months 95.56 3.87 4.41 25°C Light yellow colour lyophilized cake
NO

*for determination of pH - one lyophilized vial reconstituted with 5 ml water for Injection.

As is evident from the above trial 9, when the pH of the bulk solution is adjusted between 3.3 to 4.3; the composition exhibits more impurities after the 3months although no particulate matter was observed.

It is observed from the above examples that, although the compositions of trail 8 and trail 9, comprising Isavuconazonium Sulfate equivalent to Isavuconazole 200 mg, sodium chloride 18 mg and Polysorbate 80 100 mg, did not yield any visible particulate matter upon reconstitution, however results in increased impurities with the increased pH range; however, the composition comprising Isavuconazonium Sulfate equivalent to Isavuconazole 200 mg, sodium chloride 18 mg and Polysorbate 80 100 mg within pH range of 1.3 to 2.3 at bulk solution stage synergistically exhibits good stability with less impurities and did not show formation of visible particulates after reconstitution of Lyophilized formulation with 5 ml sterile water for injection and further diluted with 250 ml 0.9%sodium chloride injection or 5% Dextrose injection and even after 3 months at 25°C in lyophilized form as shown in Trial 7.

Thus the present freeze dried compositions of Isavuconazonium Sulfate avoids the need to use in-line filter with a microporous membrane pore size of 0.2 to 1.2 micron and in-line filter reminder sticker to the infusion bag, as it is stable at room temperature (25°C) and further devoid of visible particulate matter and hence is cost-effective when compared to innovator’s CRESEMBA.