DESC:FORM 2

THE PATENTS ACT 1970
(SECTION 39 OF 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See section 10; rule 13)

“Lyophilized composition comprising cyclophosphamide monohydrate”

ALEMBIC PHARMACEUTICALS LIMITED
An Indian Company
Alembic Campus, Alembic Road, Vadodara-390 003,
Gujarat, India.

The following specification describes the invention and the manner in which it is to be performed:

FIELD OF THE INVENTION
The present subject matter relates to a lyophilized composition comprising cyclophosphamide monohydrate. The subject matter also relates to a lyophilized composition comprising cyclophosphamide monohydrate used for injection. The subject matter further relates to a process for preparing such lyophilized cyclophosphamide monohydrate composition.
BACKGROUND OF THE INVENTION
Cyclophosphamide is a synthetic antineoplastic drug chemically related to the nitrogen mustards and has the following structure:

Cyclophosphamide is used to treat various types of cancers and few autoimmune disorders. Cyclophosphamide exists at least in monohydrate and anhydrous forms. Monohydrate is a stable form but under dry conditions (relative humidity of about 20% or less) it begins to lose its water of hydration which can cause problems in manufacturing. Hence maintaining the manufacturing and storage temperatures for this product is extremely important.
The U.S patent number US 4,537,883 discloses a stable rapidly dissolving lyophilized and hydrated composition of cyclophosphamide with sodium bicarbonate. The disadvantages associated with the product described in this patent are the large size of the vials required for lyophilization and time taken to solubilize the product.
The U.S patent number US 4,659,699 discloses the process for freeze drying of cyclophosphamide. The two stage process described in the patent involves freeze drying of an aqueous solution of cyclophosphamide to yield a hydrate of cyclophosphamide. In the first stage, cyclophosphamide is freeze dried with an excipient until the moisture content is less than 2% by weight. In the second stage, the freeze dried material is rehydrated until the moisture content of the product is in the critical range i.e. 2-7% by weight. The process described in this patent requires the use of high quantity of excipients for maintaining the stability of the product.
The PCT publication number WO 2014068585 discloses the process for producing lyophilized compositions of cyclophosphamide monohydrate, wherein the process does not need rehydration step. The lyophilization is carried out in presence of solvent or mixture of solvents.
The Canadian patent application number CA 2063058 discloses a process for hydrating a lyophilized composition of cyclophosphamide having a hydrated form as its most stable form and a bulking agent. The process comprises contacting the lyophilized composition with atomized water in a sealed chamber maintained at a reduced pressure, maintaining the relative humidity in the chamber at greater than 90% and, preferably, greater than 95% for a period of time sufficient to convert the composition to its most stable hydrated form, and recovering the hydrated composition.
The Indian patent application number IN 212/MUM/2013 discloses a lyophilized cyclophosphamide injection in a unit dosage form with appropriate lyo-protection using the direct lyophilization process with short lyo-cycle to overcome the cumbersome lyophilization processes employed in prior art.
In the past, a pharmaceutical composition has been marketed, containing the cyclophosphamide monohydrate in the form of a coarse powder, mixed with common salt for the purpose of making it flowable through hopper. Currently available formulation of cyclophosphamide monohydrate for injection is sterile powder filling which includes sodium chloride as an aid to increase flow property. Such powder filling may not be readily reconstituted in water and hence external heating of the glass vials may be required with long reconstitution time.
However, in the manufacturing practice, powder filling tends to be difficult. In addition, during the processing and storage of dry powder premix formulation, a glassiness and or stickiness could be acquired by the premix composition giving unattractive material with inferior solubility characteristics and decreased potency.
Therefore, the above compositions have been replaced by freeze-dried cyclophosphamide monohydrate compositions. The technique known as lyophilization is often employed for freeze-dried injectable pharmaceuticals which exhibit poor stability in aqueous solution. This process involves freeze drying the frozen solutions leaving only solid dried components of the original liquid.
Cyclophosphamide monohydrate as such is a stable form, but it loses water at high temperatures. Hence, maintaining proper vacuum and temperature during manufacturing is important. Therefore, there is a need to develop a composition comprising cyclophosphamide monohydrate that overcomes the disadvantages of compositions and processes known in the art.
The inventors of the present subject matter have surprisingly found that it is possible to prepare a stable cyclophosphamide monohydrate lyophilized composition for injection prepared by a process comprising lyophlization of a solution comprising cyclophosphamide monohydrate, dehydrated alcohol and water for injection.

OBJECT OF THE INVENTION
An object of the present subject matter is to provide a lyophilized composition comprising cyclophosphamide monohydrate.
In one aspect, there is provided a lyophilized composition prepared by a process comprising lyophlization of a solution comprising cyclophosphamide monohydrate and dehydrated alcohol or mixture of dehydrated alcohol and water for injection in suitable proportions and optionally comprising other excipients.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate, wherein the composition retains cyclophosphamide monohydrate after lyophilization process.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate, wherein the composition retains cyclophosphamide monohydrate during storage i.e. shelf-life.
SUMMARY OF THE INVENTION
The present subject matter relates to a lyophilized composition comprising cyclophosphamide monohydrate. The subject matter also relates to a lyophilized composition comprising cyclophosphamide monohydrate used for injection. The subject matter further relates to a process for preparing such lyophilized cyclophosphamide monohydrate composition.
In one aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate.
In one embodiment, the lyophilized composition of cyclophosphamide monohydrate is used for injection.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate prepared by a process comprising lyophilization of a solution comprising cyclophosphamide monohydrate and dehydrated alcohol or a mixture of dehydrated alcohol and water for injection.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate, wherein the composition remains stable for at least 6 months when stored at 25°C and 60% RH.
In another aspect, there is provided a stable lyophilized composition comprising cyclophosphamide monohydrate, wherein the composition has water content of not less than 5.7%.
In another aspect, there is provided a stable lyophilized composition comprising cyclophosphamide monohydrate prepared by a process comprising steps of:
a) dissolving cyclophosphamide monohydrate in dehydrated alcohol under continuous stirring,
b) adding water for injection under continuous stirring to step (a) and making up the volume with dehydrated alcohol,
c) filtering the solution of step (b), and
d) lyophilizing solution of step (c) in a lyophilizer.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an overlay of X-ray powder diffraction pattern of cyclophosphamide monohydrate USP and that of a formulation prepared according to example 8.
DETAILED DESCRIPTION OF THE INVENTION
The present subject matter relates to a lyophilized composition comprising cyclophosphamide monohydrate. The subject matter also relates to a lyophilized composition comprising cyclophosphamide monohydrate used for injection. The subject matter further relates to a process for preparing such lyophilized cyclophosphamide monohydrate composition.
The present subject matter described herein is directed to a lyophilized composition comprising cyclophosphamide monohydrate.
In an embodiment, a lyophilized composition comprising cyclophosphamide monohydrate is used for injection.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate prepared by a process comprising lyophilization of a solution comprising cyclophosphamide monohydrate and dehydrated alcohol or a mixture of dehydrated alcohol and water for injection in suitable proportions.
In another embodiment, the lyophilized composition comprising cyclophosphamide monohydrate prepared by a process comprising lyophilization of a solution comprising cyclophosphamide monohydrate and dehydrated alcohol or mixture of dehydrated alcohol and water for injection in suitable proportions and optionally comprising other excipients.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate, wherein the composition retains at least 50% w/w of cyclophosphamide in monohydrate form after lyophilization process.
In another embodiment, a lyophilized composition retains at least 60% w/w, at least 70% w/w, at least 80% w/w or at least 90% w/w of cyclophosphamide in monohydrate form after lyophilization process.
In another embodiment, a lyophilized composition retains about 100% w/w of cyclophosphamide in monohydrate form after lyophilization process.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate, wherein the composition retains at least 50% w/w of cyclophosphamide monohydrate during storage i.e. shelf-life.
In another embodiment, a lyophilized composition retains at least 60% w/w, at least 70% w/w, at least 80% w/w or at least 90% w/w of cyclophosphamide monohydrate during storage i.e. shelf-life.
In another embodiment, a lyophilized composition retains about 100% w/w of cyclophosphamide monohydrate during storage i.e. shelf-life.
In another embodiment, a lyophilized composition retains at least 90% w/w of cyclophosphamide monohydrate when stored for 12 months at 2 °C to 8 °C.For the purpose of the present subject matter, cyclophosphamide is a base or hydrate or a pharmaceutically acceptable salt or hydrate thereof and in crystalline or amorphous forms thereof.
The phrase "pharmaceutically acceptable salt(s) or hydrate(s)", as used herein, unless otherwise indicated, includes salts or hydrates of cyclophosphamide. The preferred form is cyclophosphamide monohydrate.
The terms “formulation or composition”, unless otherwise specified, are used synonymously in the present specification.
The term "dehydrated alcohol or dehydrated alcohol USP or ethanol or dehydrated ethanol” as used herein, unless otherwise indicated, is specific grade of ethanol that contains not less than (NLT) 99.2 % by weight, corresponding to NLT 99.5% by volume, at 15.56 °C, of C2H5OH.
The term “stability” of composition refers to the ability of composition to retain at least 50% w/w of cyclophosphamide in monohydrate form and at least 90% w/w of the potency of cyclophosphamide monohydrate. Further, the composition is deemed to be stable if it retains at least 50% w/w of cyclophosphamide in monohydrate form and at least 90% w/w of the potency of cyclophosphamide monohydrate.
The term “water content” as used in the present subject matter refers to the total content of water present in the composition as determined by Karl Fischer method.
The term “reconstitution time” as used in the present subject matter refers to the time required for complete dissolution of the lyophilized composition in reconstitution medium such as water for injection and like.
Impurities may be present in formulation at initial and/or during shelf life. Such impurities can be identified by methods known in the art and can be specified as impurity A, B, C, D etc. or sometimes if the impurity/ impurities are not specified it can be deemed as unknown impurities. The present subject matter provides a process for manufacturing a lyophilized composition comprising cyclophosphamide monohydrate intended for parenteral administration.
In another aspect, there is provided a lyophilized cyclophosphamide monohydrate injection in a unit dosage form without a lyo-protectant. This could be achieved by employing a direct lyophilization process with short lyo cycle as described herein to overcome the cumbersome lyophilization processes employed in prior art.
Freeze drying process involves removal of solvent from a frozen mass under reduced atmospheric pressure. In the context of this subject matter the term freeze drying, drying and lyophilization shall be used interchangeably. Lyophilization helps to stabilize pharmaceutical composition by reducing the solvent component(s) to levels that no longer support chemical reactions or biological growth. Since drying during lyophilization takes place at a low temperature, chemical decomposition is also reduced.
The use of organic solvents requires more attention in the freeze drying process. Lower temperatures are required to freeze and condense solvents and they can easily bypass the condenser and end up causing damage to the vacuum pump. However, special filter cartridges or liquid nitrogen (LN2) traps may be required to catch/condense certain solvents with very low freezing temperatures or dry vacuum pumps are used. The freezing temperature of ethanol is -114.1 °C, that of tertiary butyl alcohol is 25°C and that of isopropyl alcohol is -89 °C.
The pharmaceutical composition of the subject matter comprises cyclophosphamide monohydrate prepared by a process comprising lyophilization of a solution comprising cyclophosphamide monohydrate and dehydrated alcohol or a mixture of dehydrated alcohol and water for injection in suitable proportions. The solvent is later removed during the freeze drying process.
Selection of solvent system
The solubility study of cyclophosphamide monohydrate in dehydrated alcohol was carried out at two different temperature ranges and the result is presented in Table 1. The quantity of cyclophosphamide monohydrate dissolved in 1 mL of ethanol is given below:
Table 1
Sr. No. Temperature Quantity in mg per mL of ethanol
1 2°C -8°C 590
2 15°C -25°C 1250
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate is prepared by a process comprising lyophilizing a solution comprising cyclophosphamide monohydrate and dehydrated alcohol.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate prepared by a process comprising lyophilizing a solution comprising cyclophosphamide monohydrate in a mixture of dehydrated alcohol and water.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate prepared by a lyophilization process, wherein the ratio of cyclophosphamide to water for injection is from about 1:0.01 to about 1:10.
In another embodiment, the ratio of cyclophosphamide to water for injection is 1:0.05 1:0.1, 1:0.17, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.8, 1:1, 1:2 or 1:4, 1:6 or 1:8.
In another embodiment, the ratio of cyclophosphamide to water for injection is about 1:0.2.
In another embodiment, the ratio of cyclophosphamide monohydrate to water for injection is 1:0.05 1:0.1, 1:0.17, 1:0.28, 1:0.37, 1:0.5, 1:0.8, 1:1, 1:2 or 1:4, 1:6 or 1:8.
In another embodiment, the ratio of cyclophosphamide monohydrate to water for injection is about 1:0.18.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate prepared by a lyophilization process, wherein the ratio of cyclophosphamide to dehydrated alcohol is from about 1:0.05 to about 1:10.
In another embodiment, the ratio of cyclophosphamide to dehydrated alcohol is 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.8, 1:0.9, 1:1, 1:2, 1:4, 1:6 or 1:8.
In another embodiment, the ratio of cyclophosphamide to dehydrated alcohol is about 1:0.63.
In another embodiment, the ratio of cyclophosphamide monohydrate to dehydrated alcohol is 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.88, 1:1, 1:18, 1:4, 1:6 or 1:8.
In another embodiment, the ratio of cyclophosphamide monohydrate to dehydrated alcohol is about 1:0.59.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate prepared by a lyophilization process, wherein the ratio of water for injection to dehydrated alcohol is from about 1:0.1 to about 1:30.
In another embodiment, the ratio of water for injection to dehydrated alcohol is 1:0.2, 1:0.4, 1:0.8, 1:1, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:6, 1:8, 1:10, 1:15, 1:20, 1:25 or 1:30.
In another embodiment, the ratio of water for injection to dehydrated alcohol is about 1:3.15.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate, wherein the composition remains stable for at least 6 months when stored at 25 °C and 60% RH.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate, wherein the composition remains stable for 12 months when stored at 2 °C to 8 °C.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate, wherein the composition contains less than about 5000 ppm of residual solvent.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate contains less than of about 5000 ppm of ethanol.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate contains less than of about 4500 ppm or less than about 3000 ppm or less than about 2000 ppm of ethanol.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate contains about 2600 ppm of ethanol.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate, wherein the composition has water content of not more than about 8% w/w
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate, wherein the composition has water content of not less than about 5.7% w/w
In another embodiment, a stable lyophilized composition comprising cyclophosphamide monohydrate, wherein the water content of the composition is about 6.4 %.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate prepared by a process comprising the steps of:
a) dissolving cyclophosphamide monohydrate in dehydrated alcohol to form a solution, and
b) filtering the solution of step (a) and lyophilizing in a lyophilizer.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate prepared by a process comprising the steps of:
a) dissolving cyclophosphamide monohydrate in dehydrated alcohol and adding water for injection to form a solution, and
b) filtering the solution of step (a) and lyophilizing in a lyophilizer.
In another aspect, there is provided a process for preparing a lyophilized composition comprising cyclophosphamide monohydrate, the process comprising steps of:
a) dissolving cyclophosphamide monohydrate in dehydrated alcohol under continuous stirring,
b) adding water for injection to step (a) to form a solution,
c) filtering the solution of step (b), and
d) lyophilizing the solution obtained in step (c) using a lyophilizer.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate prepared by a process comprising the steps of:
a) collecting dehydrated alcohol in to a vessel, cooling to 2-8°C
b) adding cyclophosphamide monohydrate under continuous stirring to step (a) and stirring until it dissolves completely,
c) adding water for injection under continuous stirring to step (b) and stirring until it is mixed homogeneously,
d) adding dehydrated alcohol to make up the final volume and mixing well under continuous stirring to get homogenous solution,
e) filtering the solution of step (d), and
f) lyophilizing the solution of step (e) using lyophilizer.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate prepared by a process comprising the steps of:
a) collecting dehydrated alcohol in to a vessel, cooling to 2-8°C
b) adding cyclophosphamide monohydrate under continuous stirring to step (a) and stirring until it dissolves completely,
c) adding water for injection under continuous stirring to step (b) and stirring until it is mixed homogeneously,
d) adding dehydrated alcohol to make up the final volume and mixing well under continuous stirring to get homogenous solution,
e) filtering the solution of step (d) using a 0.22 µm filter and filling into sterile vials, and
f) lyophilizing the filled vials of step (e) using a lyophilizer.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate prepared by a process comprising steps of:
a) dissolving cyclophosphamide monohydrate in dehydrated alcohol and adding water for injection to form a solution,
b) filtering the solution of step (a) and lyophilizing the material obtained in step (a) in a lyophilizer,
wherein 2°C to 8°C temperature is maintained throughout the manufacturing process.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate prepared by a process comprising steps of:
a) collecting dehydrated alcohol in to a vessel and cooling to 2°C to 8°C,
b) adding cyclophosphamide monohydrate under continuous stirring to step (a),
c) adding water for injection under continuous stirring to step (b),
d) adding dehydrated alcohol to make up the final volume sufficient to batch size,
e) filtering the solution of step (d) and lyophilizing the filtrate using lyophilizer.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate prepared by a process comprising steps of:
a) collecting dehydrated alcohol in to a vessel and cooling to 2°C to 8°C,
b) adding cyclophosphamide monohydrate under continuous stirring to step (a) and stirring until it dissolves completely,
c) adding water for injection under continuous stirring to step (b) and stirring until it is mixed homogeneously,
d) adding dehydrated alcohol to make up the final volume sufficient to batch size and mixing well under continuous stirring to get clear and homogenous solution,
e) filtering the solution of step (d) and lyophilizing the filtrate using lyophilizer,
wherein 2°C to 8°C temperature is maintained throughout the manufacturing process after step (c).
In another embodiment, a lyophilization process comprises rapidly freezing solution comprising cyclophosphamide monohydrate and then employing a chamber pressure of about 150 mTorr with shelf temperature from about -55°C to about -40°C.
In another embodiment, the shelf temperature is raised to -25°C with 600mTorr chamber pressure while continuing the lyophilization.
In another embodiment, the shelf temperature is raised to -25°C with 600mTorr chamber pressure and continuing the lyophilization up to 5.0°C followed by cycle end.
In another embodiment, the lyophilization involves drying or sublimation at temperature of about -55°C to -40°C using chamber pressure 100 to 150mTorr.
It was observed that lyophilization employing traditional/usual freezing temperature (-45°C to -50°C) do not result in complete freezing. Most of the vials were not frozen and were observed to be liquefied i.e. collapsed vials observed at end of lyophilization cycle. This may be due to insufficient evaporation of alcohol from vials. Surprisingly, inventors have found that when freezing step was carried at about -55°C, powder in the vials was not collapsed.
In another embodiment, the freezing temperature at the end of freezing step is about -55 °C.
In another embodiment, during lyophilization the vacuum is applied at the end of freezing step at about -55 °C.
In another embodiment, the lyophilization process comprises steps of:
a) rapid freezing to about -55°C and applying chamber vacuum about 100mTorr at about -55°C,
b) employing a chamber pressure of about 100 mTorr with shelf temperature from about -55°C to about -40°C,
c) raising the shelf temperature to about -25°C with 600mTorr chamber pressure, and
d) drying or sublimation process at temperature of about -55°C to about -40 °C using chamber pressure from about 100 to about 150mTorr.
In another embodiment, the lyophilization process comprises steps of:
a) rapid freezing to about -55°C and applying chamber vacuum about 150mTorr at about -55°C,
b) employing a chamber pressure of about 150 mTorr with shelf temperature from about -55°C to about -40°C,
c) raising the shelf temperature to about -25°C with 600mTorr chamber pressure, and
d) drying or sublimation process at temperature of about -55°C to about -40 °C using chamber pressure from about 100 to about 150mTorr.
In another embodiment, the lyophilization process comprises steps of:
a) rapid freezing to about -55°C and applying chamber vacuum about 200mTorr at about -55°C,
b) employing a chamber pressure of about 200 mTorr with shelf temperature from about -55°C to about -40°C,
c) raising the shelf temperature to about -15°C with 600mTorr chamber pressure, and
d) drying or sublimation process at temperature of about -55°C to about -40 °C using chamber pressure from about 200 to about 300mTorr.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate prepared by a process comprising steps of:
a) collecting dehydrated alcohol in to a vessel and cooling to 2°C to 8°C,
b) adding cyclophosphamide monohydrate under continuous stirring to step (a) and stirring until it dissolves completely,
c) adding water for injection under continuous stirring to step (b) and stirring until it is mixed homogeneously,
d) adding dehydrated alcohol to make up the final volume sufficient to batch size and mixing well under continuous stirring to get clear and homogenous solution,
e) filtering the solution of step (d) and lyophilizing the filtrate using lyophilizer,
wherein lyophilization process comprises steps of:
i. rapidly freezing to -55°C and applying chamber vacuum 150mTorr at -55°C,
ii. employing a chamber pressure of about 150 mTorr with shelf temperature from -55°C to -40°C,
iii. raising the shelf temperature to -25°C with 600mTorr chamber pressure, and
iv. drying or sublimation process at temperature of about -55°C to -40 °C using chamber pressure 100 to 150mTorr.
In another embodiment, cyclophosphamide monohydrate is dissolved in dehydrated alcohol at temperature of 2°C to 29°C and this solution is subjected to lyophilization.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate, wherein the total impurity is not more than about 5% w/w and an individual unspecified impurity is not more than about 0.4% w/w when stored for at least 6 months at 25 °C and 60% RH.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate, wherein the total impurity is not more than about 3% w/w and an individual unspecified impurity is not more than about 0.2% w/w when stored for at least 6 months at 25 °C and 60% RH.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate, wherein the total impurity is not more than about 4% w/w and maximum unknown impurity is not more than about 0.8% w/w when stored for at least 12 months at 25 °C and 60% RH.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate, wherein the related compound A is not more than 0.5% when stored for at least 12 months at 25 °C and 60% RH.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate, wherein the related compound B is not more than 0.1% when stored for at least 12 months at 25 °C and 60% RH.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate, wherein the related compound C is not more than 0.05% when stored for at least 12 months at 25 °C and 60% RH.
In another embodiment, a lyophilized composition comprising cyclophosphamide monohydrate, wherein the related compound D is not more than 1.5% when stored for at least 12 months at 25 °C and 60% RH.
In another aspect, there is provided a lyophilized composition comprising cyclophosphamide monohydrate, wherein the reconstitution time of a composition is less than about 5 minutes.
In another embodiment, the reconstitution time of a composition is less than about 4.5 minutes, about 4 minutes, about 3.5 minutes, about 3 minutes, about 2.5 minutes, about 2 minutes, about 1.5 minutes, about 1 minute or about 0.5 minute.
In another embodiment, the reconstitution time of a composition is less than about 3 minutes.
EXAMPLES
Table 1.
Sr. No. Ingredients Qty per mL
Example 1 Example 2 Example 3 Example 4
1 Cyclophosphamide monohydrate 534.5 mg 356.34 mg 267.25 mg 534.5mg
2 Water for Injection 0.1 mL 0.1 mL 0.1 mL 0.2 mL
3 Dehydrated alcohol 0.4 mL & q.s. 1 mL 0.4 mL & q.s. 1 mL 0.4 mL & q.s. 1 mL 0.4 mL & q.s. 1 mL
Table 2.
Sr. No. Ingredients Qty per mL
Example 5 Example 6 Example 7 Example 8
1 Cyclophosphamide monohydrate 534.5mg 534.5mg 267.25 mg 356.34 mg
2 Water for Injection 0.05 mL - 0.2 mL 0.06 mL
3 Dehydrated alcohol 0.4 mL & q.s. 1 mL 0.4 mL & q.s. 1 mL 0.4 mL & q.s. 1 mL 0.4 mL & q.s. 1 mL
MANUFACTURING PROCESS
Manufacturing Process – 1:
a) Dispensed required quantity of cyclophosphamide monohydrate and dehydrated alcohol for batch as per manufacturing formula,
b) Collected dehydrated alcohol in to vessel and cooled to 2°C - 8°C,
c) Added cyclophosphamide monohydrate under continuous stirring to step (b) and stirred until it dissolved completely,
d) Added the dispensed quantity of water (except Example 6) under continuous stirring to step (c), and stirred until it mixed homogeneously,
e) Final volume was made up to with dehydrated alcohol quantity sufficient to batch size and mixed well under continuous stirring to get clear and homogenous solution, and
f) Filtered the solution of step (e) and lyophilized using lyophilizer.
Note:. After step (b), 2°C-8°C cooling was maintained throughout remaining manufacturing steps till lyophilization. During lyophilization, at end of freezing step at -55°C vacuum was applied

Manufacturing Process – 2:
a) Dispensed required quantity of cyclophosphamide monohydrate and dehydrated alcohol for batch as per manufacturing formula,
b) Collected dehydrated alcohol in to vessel,
c) Added cyclophosphamide monohydrate under continuous stirring to step (b) and stirred until it dissolves completely,
d) Added the dispensed quantity of water (except Example 6) under continuous stirring to step (c), and stirred until it mixed homogeneously,
e) Final volume was made up with dehydrated alcohol quantity sufficient to batch size and mixed well under continuous stirring to get clear and homogenous solution, and
f) Filtered the solution of step (e) and lyophilized using lyophilizer.
Note: During lyophilization, at end of freezing step at -55°C vacuum was applied.
Physicochemical Parameters
The examples 1 and 8 followed manufacturing process 1 and resulting lyophilized composition was evaluated for its water content and the results are presented in table 3, as below:
Table 3.
Water content (in %)
Example # Vial 1 Vial 2 Vial 3 Average
Example 1 6.41 6.42 6.48 6.44
Example 8 6.36 6.57 6.53 6.49
Stability data
Physicochemical parameters of samples from example 2 prepared using manufacturing process 1 were evaluated at initial and for samples stored at 25°C/60% RH for 6 months and the results are presented in table 4, as below:
Table 4.
Tests Initial Data 6M 25°C/60% RH
Assay 90.0 90.9
Water content Vial 1 Vial 2 Vial 1 Vial 2
6.25 6.26 6.35 5.81

Physicochemical parameters of samples from Example 8 prepared using manufacturing process 1 were evaluated at initial and for samples stored at 25°C/60% RH for 12 months and the results are presented table 5, as below:
Table 5.
Tests Initial Data 12M 25°C/60% RH
Alcohol Content 2600 ppm NA
Water content 6.49 % 5.8 %
Related Substances (%)
Related compound A ND 0.343
Related compound B 0.128 0.078
Related compound C ND 0.035
Related compound D 0.086 1.238
Max unknown 0.011 0.685
Total Impurities 0.258 3.547 ,CLAIMS:1. A lyophilized composition comprising cyclophosphamide monohydrate prepared by a process comprising lyophilization of a solution comprising cyclophosphamide monohydrate and dehydrated alcohol or mixture of dehydrated alcohol and water for injection.
2. The lyophilized composition of claim 1, wherein a process comprises lyophilization of a solution comprising cyclophosphamide monohydrate and mixture of dehydrated alcohol and water for injection.
3. The lyophilized composition of claim 2, wherein the ratio of water for injection to dehydrated alcohol is from about 1:0.1 to about 1:30.
4. The lyophilized composition of claim 2, wherein the ratio of cyclophosphamide to water for injection is from about 1:0.05 to about 1:1.
5. The lyophilized composition of claim 2, wherein the composition contains less than about 5000 ppm of ethanol.
6. The lyophilized composition of claim 2, wherein the water content of the composition is not less than about 5.7% w/w.
7. The lyophilized composition of claim 1, wherein the total impurity is not more than about 5% w/w and an individual unspecified impurity is not more than about 0.2% w/w when stored for at least 6 months at 25°C and 60% RH.
8. The lyophilized composition of claim 1, wherein the reconstitution time of the composition is less than about 4.5 minutes.
9. The lyophilized composition of claim 1, wherein the lyophilization process comprises:
a) rapidly freezing to -55°C and applying chamber vacuum 150mTorr at -55°C,
b) employing a chamber pressure of about 150 mTorr with shelf temperature from -55°C to -40°C,
c) raising the shelf temperature to -25°C with 600mTorr chamber pressure and
d) drying or sublimation process at temperature of about -55°C to -40 °C using chamber pressure 100 to 150mTorr.
10. A process for preparing lyophilized composition comprising cyclophosphamide monohydrate comprising steps of:
a) collecting dehydrated alcohol in to a vessel,
b) adding cyclophosphamide monohydrate under continuous stirring to step (a) and stirring until it dissolves completely,
c) adding water for injection under continuous stirring to step (b) and stirring until it is mixed homogeneously,
d) adding dehydrated alcohol to make up the final volume and mixing well under continuous stirring to get clear and homogenous solution,
e) filtering the solution of step (d) and lyophilizing using a lyophilizer.