Title of Invention	A STERILE, LOW TOXICITY, STABLE, AQUEOUS, PHARMACEUTICAL COMPOSITIONS COMPRISING OXAZAPHOSPHORINE ANTINEOPLASTIC FOR PARENTERAL ADMINISTRATION
Abstract	A sterile, low toxicity, stable, aqueous, oxazaphosphorine-containing composition with mesna for parenteral administration has been described. The invention describes compositions that are stable and have low urotoxicity.

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FORM 2 THE PATENTS ACT, 1970 COMPLETE SPECIFICATION [See section 10] Title "A sterile, low toxicity, stable, aqueous, pharmaceutical compositions comprising oxazaphosphorine antineoplastic for parenteral administration" Applicant Bharat Serums & Vaccines Ltd., Road No. 27, Wagle Estate, Thane - 400 604. Maharashtra, India. Indian company incorporated under the Companies Act 1956. 25-4-2008 The following specification particularly describes and ascertains the nature of the invention and the manner in which it is to be performed GRANTED 9 MAR 2004 This invention relates to a sterile, low toxicity, stable aqueous, pharmaceutical compositions comprising oxazaphosphorine antineoplastic for parenteral administration in human beings and other mammals. The invention particularly relates to compositions comprising an oxazaphosphorine antineoplastic, mesna and an etherified ß-cyclodextrin. The invention more particularly relates to sterile, low toxicity, stable, aqueous, pharmaceutical compositions comprising Ifosfamide, Mesna, and 2-hydroxypropyl-ß-cyclodextrin (referred to hereinafter as "HPBCD"), that are stable and suitable for ready clinical use. Background and prior art: Two main groups of drugs used in the treatment of malignant disease are alkylating agents and the antimetabolites. Ifosfamide and cyclophosphamide are oxazaphosphorine antineoplastic drugs belonging to the alkylating agents group and are being widely used. Ifosfamide is given intravenously either by injection as a solution diluted to less than 4% or by infusion and is used in the treatment of a variety of solid tumours including those of the cervix, endometrium, lung, ovary, testes and thymus as well as in sarcoma and in the treatment of Burkitts lymphoma. Ifosfamide is the Approved Name for 3-(2-chloroethyl)-2-[(2-chloroethyl)amino]tetrahydro-2H- l,3,2-oxazaphosphorin-2-oxide and is represented by the formula: IFOSFAMIDE It is a white hygroscopic crystalline powder having a low melting point of 40°C. It also begins to sinter below its melting point. These characteristics of Ifosfamide make it difficult for sterile filling of the dry powder as both temperature and humidity are required to be accurately controlled. Further, as Ifosfamide powder is filled aseptically into sterile containers, maximum precautions are required to maintain sterility of the product. Ifosfamide powder is freely soluble in water. The aqueous solution is sensitive to changes in pH. The treatment with Ifosfamide is associated with serious side effects like hemorrhagic cystitis, myelosuppression, cardiac arrythmias, CNS disturbances, nephrotoxicity, haematological and gastro-intestinal reactions. Similar problems are encountered with other oxazaphosphorine antineoplastic, e.g. Cyclophosphamide, which is the Approved Name for 2-[bis(2-chloroethyl)amino]tetrahydro-2H-1,3,2-oxazophosphorine 2-oxide, represented by the formula: CYCLOPHOSPHAMIDE Oxazaphosphorine antineoplastics are toxic to the urinary tract and may involve the kidneys as well as the bladder. Hence it is recommended that they are administered in association with 2-mercaptoethanesulphonates, especially Mesna. Mesna is the Approved Name for sodium 2-mercaptoethanesulphonate and is represented by the formula: HSCH2CH2SO3 Na+. Mesna is highly water soluble. It is used for the prophylaxis of urothelial toxicity in patients being treated with Ifosfamide or Cyclophosphamide. In the kidney Mesna disulfide, the inactive metabolite of Mesna is reduced to free Mesna, which has thiol groups that react with the metabolites of Ifosfamide, and Cyclophosphamide, including acroleil, considered to be responsible for the toxic effects on the bladder. Commercially Mesna is available as sterile, nonpyrogenic aqueous solution for injection containing lOOmg/ml of Mesna The intravenous daily dose of Mesna is calculated to equal 60% of the total daily dose of Ifosfamide and is administered as 3 bolus doses given 15 minutes before and 4 and 8 hours after administration of each dose of Ifosfamide when the Ifosfamide dose is less than 2.5g/m2/day administered as a short infusion. For use with continuous infusion of Ifosfamide, Mesna may be administered as a bolus dose equal to 20% of the total Ifosfamide dose followed by a continuous infusion of mesna equal to 40% of the Ifosfamide dose, continuing for 12 to 24 hours after completion of the Ifosfamide infusion. Mesna has also been administered as a continuous infusion at a dose equal to 60% of Ifosfamide dose. No clinical data is available to justify Mesna doses greater than 60% w/w of Ifosfamide for standard doses of Ifosfamide. With high doses in excess of 2.5g/m2 of Ifosfamide, continuous and prolonged Mesna dosage regimen is necessary for maximum protection against urotoxicity. The disadvantages with the existing commercially available oxazaphosphorine products in powder form and Mesna Injection are 1. more than one vial of Ifosfamide is required to be reconstituted and then diluted to the required concentration as the standard dosage is more than lg daily. 2. in high dosage Ifosfamide therapy as high as eight vials of lg are required to be reconstituted and diluted to the required concentration. 3. as Mesna is required to be administered along with Ifosfamide, Ifosfamide solution after reconstitution is required to be mixed with Mesna. Attempts were made by various laboratories / inventors to formulate ready-to-use parenteral solution that would contain Ifosfamide and Mesna to overcome the problem of handling Ifosfamide during reconstitution and during mixing with Mesna. US-A-4959215 discloses a stable Ifosfamide-Mesna lyophilizate comprising Ifosfamide, 0.05 to 1.0 parts by weight of Mesna and 0.1 to 17 parts by weight of a hexitol prepared by freeze drying an aqueous or aqueous-ethanolic solution of Ifosfamide, Mesna and the hexitol, preferably mannitol. There is no reference to the presence of any cyclodextrin. The lyophilizate is stable physically showing no discolouration. The speed of dissolution is also claimed to markedly higher compared to the dry filled Ifosfamide. US-A-4952575 discloses a composition comprising 10 to 70 %w/v of an oxazaphosphorine of the formula: in which at least two of R1, R2 and R3 independently are 2-chloroethyl or 2-methanesulfonyloxyethyl and any remaining R radical is selected from hydrogen, methyl and ethyl; dissolved in 80 to 100 %v/v of ethanol. Even though the degradation has been shown to be minimal for Ifosfamide, use of solvents in such a high concentration leads to other problems such as volatility, handling during manufacturing, miscibility with blood. As ethanol is pharmacologically active, this may also affect the person on administration of alcoholic solution of Ifosfamide. WO-A-9918973 discloses stable ready-to-use liquid compositions of at least one oxazaphosphorine of the formula: in which R1, R2 and R3 independently are methyl, ethyl, 2-chloroethyl, 2-methanesulfonyloxyethyl or, except for R3, hydrogen, and at least two of R1, R2 and R3 are 2-chloroethyl and/or 2-methanesulfonyloxyethyl. The solution also comprises Sodium chloride which forms chloride ions in aqueous solution, and optionally, Urea / ethanol as solubilizing agent. US-A-4879286 discloses a storage-stable liquid oncolytic formulation of Cyclophosphamide formulated as a ready-to-dilute solution in a carrier comprising 50 to 100 % organic polyol selected from propylene glycol, polyethylene glycol and glycerol and 0 to 50 % water. The formulation may be used in combination with alcohols, such as 10 to 30% of ethanol (based on total weight of the formulation). Object: The main objective of this invention is thus to develop a stable composition comprising oxazaphosphorine antineoplastic together with Mesna that has low urotoxicity and suitable for parenteral administration in human beings and mammals. Yet another object of the invention is to develop the composition that will reduce the other dose dependant toxicities of oxazaphosphorine antineoplastic particularly that of Ifosfamide. Summary of the invention : Accordingly, the present invention relates to a sterile, low toxicity, stable aqueous, pharmaceutical compositions comprising an oxazaphosphorine antineoplastic, mesna and an etherified ß-cyclodextrin, suitable for parenteral administration in human beings and other mammals. The process comprising the steps of: i) adding the oxazaphosphorine antineoplastic to an aqueous solution of an etherified p-cyclodextrin; ii) adding mesna as such or as an aqueous solution optionally containing an etherified ß-cyclodextrin to the oxazaphosphorine solution of step (i); and iii) mixing the resultant aqueous solution and, optionally, making up the volume with water. Detailed description of the invention The widely used oxazaphosphorine antineoplastic agents belonging to the alkylating agents are Cyclophosphamide and Ifosfamide and are represented by the general formula Formula I Wherein, R1 = R2 = chloroethyl & R3 = hydrogen for Cyclophosphamide and R1 = R3 = chloroethyl & R2 = hydrogen for Ifosfamide. The ratio of oxazaphosphorine antineoplastic to mesna is usually in the range of about 1 : 0.05 to about 1 . 2 on a weight basis, preferably in the range of about 1 : 0.1 to about 1 : 1 on a weight basis. In the composition of the present invention, the oxazaphosphorine antineoplastic is preferably Ifosfamide or Cyclophosphamide. More preferably the oxazaphosphorine antineoplastic is Ifosfamide. The content of the Ifosfamide in the composition is from about 1 mg/ml to about 1000 mg/ml, preferably from about 25 mg/ml to about 750 mg/ml, and more preferably from about 50 mg/ml to about 500 mg/ml. The etherified (3-cyclodextrin preferably has at least some of the hydroxy groups etherified with hydroxyalkyl groups and optionally others etherified with alkyl groups and a water-solubility of more than about 1.8 g/100 ml water. Preferably the hydroxyalkyl groups are hydroxyethyl, dihydroxypropyl or, especially, hydroxypropyl groups and the alkyl groups, if present, are methyl or ethyl groups; In the composition of the present invention the etherified 3-cyclodextrin is preferably Hydroxypropyl Beta Cyclodextrin (HPBCD). The molar substitution (MS) by hydroxypropyl groups (calculated as moles of alkylating alkylene oxide per anhydroglucose unit) suitably is about 0.05 to about 10, preferably about 0.2 to about 2 and more preferably about 0.5 to 1.2 . The content of Hydroxypropyl Beta Cyclodextrin in the composition is from about 1% to about 60% w/v, preferably about 2.5% to about 40% w/v, more preferably about 5% to about 20% w/v. The compositions of the present invention may contain conventional parenteral additives such as buffers, isotonic diluents, anticrystallising agents, sequestering agents, or antioxidants. Buffers are selected from a group of pharmaceutically acceptable compounds such as citric acid, sodium citrate, potassium citrate, glycine, phosphoric acid, sodium phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, potassium phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, Histidine, Histidine hydrochloride, sodium hydroxide, potassium hydroxide, hydrochloric acid. Preferably the buffer used is a mixture of sodium dihydrogen phosphate and disodium hydrogen phosphate. The process of making the compositions of the present invention comprises the steps of: i) adding the oxazaphosphorine antineoplastic to an aqueous solution of an etherified ß-cyclodextrin; ii) adding mesna as such or as an aqueous solution optionally containing an etherified ß-cyclodextrin to the oxazaphosphorine solution of step (i); and iii) mixing the resultant aqueous solution and, optionally, making up the volume with water. The conventional parenteral additives may be present in the aqueous solution to which oxazaphosphorine antineoplastic is added and / or in the aqueous solution to which mesna is added. These additives may also be added separately as a solution in water either before adding mesna to oxazaphosphorine solution or before making up the volume. The aqueous solutions are mixed, preferably by intimate stirring and the resultant solution is usually sterilized by filtering through a sterilising grade filter. Preferably, the solution is filtered through 2\x filter followed by 0.2µ, sterilising grade filter. Usually, the filtrate will be aseptically filled into sterile containers such as vials, ampoules, plastic containers and sealing the filled containers. The one embodiment of the invention the composition of the present invention comprises HPBCD (with MS 0.5 to 1.2) from about 1% to about 60% w/v, and Ifosfamide from about 1 mg/ml to about 1000 mg/ml and weight ratio of Ifosfamide to mesna is in the range of about 1:0.05 to about 1: 2. In another embodiment of the invention the composition of the present invention comprises Ifosfamide 4-60 %w/v; Mesna 0.8-50%w/v; HPBCD (with MS 0.5 to 1.2) 2 - 15%w/v; Disodium hydrogen phosphate up to 0.5%w/v; Sodium dihydrogen phosphate up to 0.5%w/v and Disodium edetate up to 0.01%w/v. In another embodiment of the invention the composition of the present invention comprises Ifosfamide 4 - 5%w/v, Mesna 0.8-5 %w/v and HPBCD (with MS 0.5 to 1.2) 5-15 %w/v; Disodium hydrogen phosphate up to 0.5%w/v; Sodium dihydrogen phosphate up to 0.5%w/v and Disodium edetate up to 0.01%w/v. In another embodiment of the invention the composition of the present invention comprises Ifosfamide 4 - 5%w/v, Mesna 0.8-5 %w/v, HPBCD (with MS 0.5 to 1.2) 5-15 %w/v and Disodium edetate 0.005 -0.01 %w/v. In another embodiment of the invention the composition of the present invention comprises Ifosfamide 40-60 %w/v; Mesna 8-50%w/v ; HPBCD (with MS 0.5 to 1.2) 2 - 10%w/v; Disodium hydrogen phosphate up to 0.5%w/v ; Sodium dihydrogen phosphate up to 0.5%w/v and Disodium edetate up to 0.01%w/v . In another embodiment of the invention the composition of the present invention comprises Ifosfamide 40-60 %w/v; Mesna 8-50%w/v; HPBCD (with MS 0.5 to 1.2) 2 - 10%w/v and Disodium edetate up to 0.01%w/v. Examples The invention will now be illustrated by way of Examples. These Examples are by way of illustration only and in no way restrict the scope of the invention. Ifosfamide used in these Examples was of parenteral grade complying with US Pharmacopoeial specifications. Mesna used in these Examples was of parenteral grade. Hydroxypropyl Beta Cyclodextrin (HPBCD) used was manufactured by Wacker Chemie having molar substitution (MS) per anhydroglucose unit by alkyl groups between 0.5 to 1.2. Equipments used were of conventional nature; the entire processing was done in an area with a controlled environment. Water used in these Examples was of parenteral grade complying with "Water for Injection" specifications. All other additives used in these Examples were of parenteral grade. Example I: The following composition was prepared by the procedure given below 1. Ifosfamide lOg 2. Mesna 2g 3. HPBCD 40g 4. Disodium hydrogen phosphate O.lg 5. Sodium dihydrogen phosphate 0.06g 6. Water q.s. to 200 ml Weighed quantities of disodium hydrogen phosphate and sodium dihydrogen phosphate were dissolved in 160 ml of water and a weighed quantity of HPBCD was added and dissolved slowly under stirring. The resultant HPBCD solution was divided into two equal parts. A weighed quantity of Ifosfamide was gradually added under stirring to one part of buffered HPBCD solution and mixed well. A weighed quantity of Mesna was gradually added under stirring to the remaining part of buffered HPBCD solution and mixed well. Mesna solution prepared above was added to Ifosfamide solution. The resulting solution was mixed together. The volume was made up to 200 ml with water. The product was filtered through a 0.2µ filter and filled aseptically in sterile glass vials. The glass vials were closed under aseptic conditions with sterile Teflon™ coated rubber bungs and sealed using flip off seals. The composition obtained in this Example was analysed for Ifosfamide content and Mesna content by high pressure liquid chromatography (HPLC) and was found to contain 52.92 mg/ml of Ifosfamide and 10.2 mg/ml of Mesna. The composition had a pH of 6.86. Example II: The composition obtained in Example I was subjected to acute toxicity studies in mice. A conventional formulation, Holoxan™ manufactured by M/s. German Remedies was reconstituted as directed by the manufacturer and was used as a control after mixing with Mesna (equivalent to 20% of Ifosfamide content). Both the drug solutions were suitably diluted with 5% Dextrose Injection and administered intravenously. Ifosfamide in the doses of 500 mg/kg, 700 mg/kg and 900 mg/kg body weight was administered in three different groups of animals, each group consisting of eight animals. The animals were kept under observation for 14 days and mortality recorded at the end of 3 days and 7 days. It was observed that the LD5o dose was higher for composition of Example I in comparison with the Conventional formulation. Conventional formulation Mortality (%) Mortality (%) Dose (mg) 3 Days 7 Days Dose (mg) 3 Days 7 Days 500 0 0 500 50 75 700 0 50 700 100 100 900 75 100 900 100 100 LD50 700 - 900 700 LD50 500 The above data clearly indicates that composition of Example I is less toxic compared to the Conventional formulation. Example III: The following composition was prepared by the procedure given below 1. Ifosfamide lOg 2. Mesna 2g 3. HPBCD 20g 4. Disodium hydrogen phosphate O.lg 5. Sodium dihydrogen phosphate 0.06g 6. Water q.s. to 200 ml Weighed quantities of disodium hydrogen phosphate and sodium dihydrogen phosphate were dissolved in 160ml of water and a weighed quantity of HPBCD was added and dissolved slowly under stirring. A weighed quantity of Ifosfamide was gradually added under stirring to the buffered HPBCD solution and mixed for 3 hours. After 3 hours, a weighed quantity of Mesna was gradually added under stirring to the buffered Ifosfamide solution. The volume was made up to 200 ml with water and filtered through a 0.2µ filter and filled aseptically in sterile glass vials. The glass vials were closed under aseptic conditions with sterile Teflon™ coated rubber bungs and sealed using flip off seals. Example IV: The following composition was prepared by the procedure given below 1. Ifosfamide lOg 2. Mesna 2g 3. HPBCD 80g 4. Disodium hydrogen phosphate O.lg 5. Sodium dihydrogen phosphate 0.06g 6. Water q.s. to 200 ml The procedure of Example I was repeated using the components in the amounts set forth above. Example V: The following composition was prepared by the procedure given below 1. Ifosfamide lOg 2. Mesna 6g 3. HPBCD 20g 4. Disodium hydrogen phosphate O.lg 5. Sodium dihydrogen phosphate 0,06g 6. Water q.s. to 200 ml The procedure of Example I was repeated using the components in the amounts set forth above. Example VI; The following composition was prepared by the procedure given below 1. Ifosfamide lOg 2. Mesna 16g 3. HPBCD 20g 4. Disodium hydrogen phosphate O.lg 5. Sodium dihydrogen phosphate 0.06g 6. Water q.s. to 200 ml The procedure of Example I was repeated using the components in the amounts set forth above. Example VII: The following composition was prepared by the procedure given below 1. Ifosfamide lOOg 2. Mesna 20g 3. HPBCD lOg 4. Water q.s. to 200 ml Weighed quantity of HPBCD was dissolved in 20ml of water. Ifosfamide was added gradually to HPBCD solution under stirring. Mixing was continued till a clear solution was obtained. Mesna was added gradually under stirring to the resultant Ifosfamide solution and mixed well till the entire quantity of Mesna went into solution. Volume was made upto 200ml with water. The composition obtained in this Example was analysed for Ifosfamide content and Mesna content and was found to contain 497.88mg/ml of Ifosfamide and 98.73mg/ml of Mesna. Example VIII: The following composition was prepared by the procedure given below 1. Ifosfamide lOOg 2. Mesna 60g 3. HPBCD lOg 4. Water q.s. to 200 ml Weighed quantity of HPBCD was dissolved in 20ml of water. Ifosfamide was added gradually to HPBCD solution under stirring. Mixing was continued till a clear solution was obtained. Mesna was added gradually under stirring to the resultant Ifosfamide solution and mixed well till the entire quantity of Mesna went into solution. Volume was made upto 200ml with water. The composition obtained in this Example was analysed for Ifosfamide content and Mesna content and was found to contain 492.02mg/ml of Ifosfamide and 296.18mg/ml of Mesna. Example DC: The following composition was prepared by the procedure given below 1. Ifosfamide 100g 2. Mesna 60g 3. HPBCD lOg 4. Disodium hydrogen phosphate 0.8g 5. Sodium dihydrogen phosphate 0.44g 6. Disodium edetate O.Olg 7. Water q.s. to 200 ml HPBCD was dissolved in 20ml of water. Ifosfamide was then added gradually to HPBCD solution under stirring. Mixing was continued till a clear solution was obtained. Mesna was added gradually under stirring to the resultant Ifosfamide solution. Disodium edetate, disodium hydrogen phosphate and sodium dihydrogen phosphate were dissolved in 10ml of water and was added to Ifosfamide-Mesna solution and mixed well. Volume was made upto 200ml with water. Example X: The following composition was prepared by the procedure given below 1. Ifosfamide 180g 2. Mesna 36g 3. HPBCD lOg 4. Water q.s. to 200 ml The procedure of Example VIII was repeated using the components in the amounts set forth above. Example XI: The following composition was prepared by the procedure given below 1. Ifosfamide lOg 2. Mesna 2g 3. HPBCD 20g 4. Disodium hydrogen phosphate O.lg 5. Sodium dihydrogen phosphate 0.06g 6. Water q.s. to 200 ml Weighed quantities of disodium hydrogen phosphate and sodium dihydrogen phosphate were dissolved in 160 ml of water and a weighed quantity of HPBCD was added and dissolved slowly under stirring. Weighed quantity of Ifosfamide was gradually added under stirring to buffered HPBCD solution and mixed for 3 hours. Weighed quantity of Mesna was gradually added under stirring to the above Ifosfamide solution and mixed well. Volume was made up to 200 ml with water. The product was filtered through a 0.2u filter and filled aseptically in sterile glass vials. The glass vials were closed under aseptic conditions with sterile Teflon™ coated rubber bungs and sealed using flip off seals. The composition obtained in this Example was analysed for Ifosfamide content and Mesna content and was found to contain 51.2mg/ml of Ifosfamide and lOmg/ml of Mesna. The composition had a pH of 7.05. Example XII: The composition obtained in Example XI along with conventional formulation Holoxan™ manufactured by M/s. German Remedies were subjected to Hemorrhagic cystitis studies in rats to evaluate the bladder toxicity. Experimental details are as follows: Animals used : Wistar rats of either sex. Weight range of animals :100-150gm. Number of groups : 5 Number of animals per group : 2 Acclimatization : One week under test conditions under controlled temperature and humidity. Test Materials Identity Description Route of administration Ifosfamide with Mesna Injection Composition of Example XI Clear colourless solution Intravenous Comparative material Identity Lot No. Manufacturing Date Expiry Date Description Strength Manufacturer Route of administration .Holoxan™ Ifosfamide injection U.S.P. G 220 October 2001 September 2003 Dry powder for reconstitution with water for injection 40 mg/ml on reconstitution German Remedies Limited. Intravenous Study design Animals were divided into 5 groups and each group comprised two animals. The animals received injections of Ifosfamide formulations as specified in table 1. Table 1 Doses of Ifosfamide Formulations. Group No. Formulation Dose (mg/kg body weight) Ifosfamide Mesna 1 Holoxan 400 80 2 Holoxan 500 100 3 Example XI 400 80 4 Example XI 500 100 5 Dextrose Inj. - - All animals received injections via the intravenous route. The animals were sacrificed 24 hours after injection. The urinary bladders of all the animals were collected and were fixed in 10% formalin for 48 hours. Histopathological slides of the organ were prepared and subjected to microscopic examination. EVALUATION: Table 2 represents the grading pattern for the hemorrhagic cystitis. Table 2 : Grading pattern for hemorrhagic cystitis. Grading Score Normal 0(N) Mild hemorrhagic cystitis 1 + Moderate hemorrhagic cystitis with or without epithelial atypia 2 + Severe hemorragic cystitis with or without epithelial atypia 3 + OBSERVATIONS: Table 3 depicts the evaluation results on hemorrhagic cystitis of two formulations of Ifosfamide Table 3 : Evaluations of two formulations of Ifosfamide for hemorrhagic cystitis. Animal No. Formulation Dose (mg/kg) Score Ifosfamide Mesna 1. Holoxan 400 80 1 + 2. Holoxan 400 80 1 + 3. Holoxan 500 100 1 + 4. Holoxan 500 100 2 + 5. Example XI 400 80 N 6. Example XI 400 80 N 7. Example XI 500 100 N 8. Example XI 500 100 N 9. Dextrose - - N 10 Dextrose - - N DISCUSSION: Animals treated with Holoxan showed hemorrhagic cystitis at both doses of 400mg/kg and 500mg/kg whereas composition of Example XI did not show hemorrhagic cystitis. CONCLUSION: The above findings conclusively proved that the composition of Example XI is less toxic than the conventional formulation Holoxan™ Example XIII: The composition obtained in Example XI was subjected to stability studies. The data is as follows : Storage condition Description Ifosfamide content Initial Clear, colourless liquid 51.2mg/ml 2°C-8°C - 3M Clear, colourless liquid 50.06mg/ml 2°C-8°C - 6M Clear, colourless liquid 50.33mg/ml Conclusion: From the above it is evident that Ifosfamide is stable in the composition obtained in Example XI without undergoing any degradation when stored at 2°C - 8°C whereas the conventional formulation on reconstitution is reported to be stable for three to six weeks under refrigeration. The advantages of the invention: In one aspect of the invention Ifosfamide and Mesna are combined with HPBCD to give an aqueous, stable composition so that the product is readily marketable and is convenient to use without the step of reconstitution and less handling. Surprisingly, the process of invention in which Ifosfamide, Mesna and HPBCD are combined has produced a composition having low toxicity showing another aspect of synergy in the composition. We Claim: 1. A sterile, low toxicity, stable, aqueous, pharmaceutical compositions comprising an oxazaphosphorine antineoplastic, mesna and an etherified ß-cyclodextrin, suitable for parenteral administration in human beings and other mammals. 2. A composition as claimed in claim 1, further comprises, conventional parenteral additives, which are selected from a group of additives such as buffers, tonicity agents, preservatives, sequestering agents, antioxidants, anticrystallising agents. 3. A composition as claimed in any of the claims 1-2, wherein the oxazaphosphorine antineoplastic is of the formula in which at least two of R1, R2 and R3 independently are 2-chloroethyl and the remaining R radical is hydrogen 4. A composition as claimed in any one of the preceding claims, wherein the weight ratio of oxazaphosphorine antineoplastic to mesna is in the range ofl:0.05tol:2. 5. A composition as claimed in Claim 3, wherein, R1 = R3 = chloroethyl & R2 = hydrogen (Ifosfamide) 6. A composition as claimed in any one of the preceding claims, wherein the etherified ß-cyclodextrin used is 2-hydroxypropyl-p-cyclodextrin. 7. A composition as claimed in Claim 6, wherein the molar substitution (MS) of 2-hydroxypropyl-3-cyclodextrin is 0.05 -10. 8. A composition as claimed in Claim 7, wherein the molar substitution (MS) of 2-hydroxypropyl-ß-cyclodextrin is 0.5 -1.2. 9. A composition as claimed in any one of the preceding claims comprising Oxazaphosphorine antineoplastic Ifosfamide from 1 mg/ml to 1000 mg/ml, mesna 0.05 to 2 times the weight of Ifosfamide and 2-hydroxypropyl-P-cyclodextrin from 1% to 60% w/v of the composition. 10. A composition as claimed in claim 9, wherein the Ifosfamide content is 25-750 mg/ml 11. A composition as claimed in claim 10, wherein the Ifosfamide content is 50-500 mg/ml 12. A composition as claimed in claim 11, wherein the Ifosfamide content is about 50 mg/ml 13. A composition as claimed in claim 11, wherein the Ifosfamide content is about 500 mg/ml 14. A composition as claimed in claim 9, wherein the weight ratio of Ifosfamide to mesna is in the range of 1:0.1 to 1: 1, 15. A composition as claimed in claim 14, wherein the weight ratio of Ifosfamide to mesna is 1:0.6. 16. A composition as claimed in claim 14, wherein the weight ratio of Ifosfamide to mesna is 1: 0.2, 17. A composition as claimed in Claim 9, wherein the concentration of 2-hydroxypropyl-ß-cyclodextrin having molar substitution from 0.5 to 1.2 is 2.5 - 40% w/v of the composition., 18. A composition as claimed in Claim 17, wherein the concentration of 2-hydroxypropyl-ß-cyclodextrin having molar substitution from 0.5 to 1.2 is 5 - 20% w/v of the composition. 19. A composition as claimed in any of the claims 1-6, comprising Ifosfamide 4-60 %w/v; Mesna 0.8-50%w/v; 2-hydroxypropyl-ß-cyclodextrin having molar substitution 0.5 to 1.2 at a concentration of 2 - 15%w/v; Disodium hydrogen phosphate up to 0.5%w/v; Sodium dihydrogen phosphate up to 0.5%w/v and Disodium edetate up to 0.01%w/v. 20. A composition as claimed in claim 19, comprising Ifosfamide 4 - 5%w/v, Mesna 0.8-5 %w/v and 2-hydroxypropyl-ß-cyclodextrin having molar substitution 0.5 to 1.2 at a concentration of 5-15 %w/v; Disodium hydrogen phosphate up to 0.5%w/v; Sodium dihydrogen phosphate up to 0.5%w/v and Disodium edetate up to 0.01%w/vv 21. A composition as claimed in claim 19, comprising Ifosfamide 4 - 5%w/v, Mesna 0.8-5%w/v, 2-hydroxypropyl-P-cyclodextrin having molar substitution 0.5 to 1.2 at a concentration of 5-15 %w/v and Disodium edetate 0.005 -0.01 %w/v. 22. A composition as claimed in claim 19, comprising Ifosfamide 40-60 %w/v; Mesna 8-50%w/v; 2-hydroxypropyl-P-cyclodextrin having molar substitution 0.5 to 1.2 at a concentration of 2 - 10%w/v; Disodium hydrogen phosphate up to 0.5%w/v; Sodium dihydrogen phosphate up to 0.5%w/v and Disodium edetate up to 0.01%w/v. 23. A composition as claimed in claim 20, comprising Ifosfamide 40-60 %w/v; Mesna 8-50%w/v; 2-hydroxypropyl-ß-cyclodextrin having molar substitution 0.5 to 1.2 at a concentration of 2 - 10%w/v and Disodium edetate up to 0.01%w/v. 24. A composition as claimed in Claim 3, wherein, R1 = R2 = chloroethyl & R3 = hydrogen (Cyclophosphamide). 25. A sterile, low toxicity, stable, aqueous, pharmaceutical compositions comprising an oxazaphosphorine antineoplastic, mesna and an etherified ß-cyclodextrin, suitable for parenteral administration in human beings and other mammals as claimed in Claim 1, obtainable by a process comprising the steps of: i) adding the oxazaphosphorine antineoplastic to an aqueous solution of an etherified P-cyclodextrin; ii) adding mesna as such or as an aqueous solution optionally containing an etherified p-cyclodextrin to the oxazaphosphorine solution of step (i); and iii) mixing the resultant aqueous solution and, optionally, making up the volume with water. 26. A low toxicity, stable oxazaphosphorine-containing composition comprising an oxazaphosphorine antineoplastic, mesna and an etherified ß-cyclodextrin substantially as herein described in the text and examples. Dated this 9th day of March. 2004 KASBEKAR MADHAV GAJANAN Agent for the Applicant To, The Controller of Patents The Patent Office At Mumhai.

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295-MUM-2004-CORRESPONDENCE(21-7-2008).pdf

295-mum-2004-correspondence(ipo)-(24-09-2008).pdf

295-mum-2004-correspondence1(28-12-2006).pdf

295-mum-2004-correspondence2(24-08-2007).pdf

295-mum-2004-correspondence2(25-04-2008).pdf

295-mum-2004-correspondence3(24-08-2007).pdf

295-mum-2004-correspondence3(25-04-2008).pdf

295-mum-2004-form 1(09-03-2004).pdf

295-mum-2004-form 13(21-07-2008).pdf

295-mum-2004-form 13(21-7-2008).pdf

295-mum-2004-form 18(28-12-2006).pdf

295-mum-2004-form 2(granted)-(25-04-2008).doc

295-mum-2004-form 2(granted)-(25-04-2008).pdf

295-mum-2004-form 26(09-03-2000).pdf

295-mum-2004-form 26(09-03-2004).pdf

295-mum-2004-form 3(09-03-2004).pdf

295-mum-2004-form 3(23-08-2007).pdf

295-mum-2004-form 3(27-08-2007).pdf