LYOPHILIZED PREPARATION OF PLATINUM COMPOUND

Abstract: The present invention relates to a lyophilized preparation comprising cis-1,1-cyclobutanedicarboxylate­ (2R)-2-methyl-1,4-butanediamine platinum (II), which is useful as an antitumor drug, and dextran. This preparation has a greatly improved resolubility.

Description: The present invention relates to a lyophilized preparation comprising cis-1,1-cyclobutanedicarboxylate(2R)-2-methyl-1,4-butanediamine platinum (II) (hereinafter referred to as the platinum compound) which is useful as an antitumor drug, and to a method for producing thereof. Generally, preparations for injection are prepared in the form of a solution, a lyophilized preparation or a powder preparation. For example, EP-A-0 021 009 discloses a lyophilized preparation comprising a water-soluble agent and dextran which can be applied to unstable compounds and does not require tabletting, of such compounds. The platinum compound is relatively unstable in aqueous solutions, so that it is highly desirable that the platinum compound be used in the form of a lyophilized preparation or a powdery preparation of its bulk drug powder, because the preparation is usually stored at room temperature over a long period of time. However, a preparation obtained merely by lyophilizing an aqueous solution of the platinum compound dissolves in water so slowly that it is necessary to conduct heating or stirring over a long period of time, when the preparation is to be redissolved. Furthermore the powder preparation dissolves more slowly than the lyophilized preparation so that redissolution is further difficult. The inventors made intensive studies to find out that when dextran is added to a solution of the platinum compound and the solution is lyophilized, the resulting preparation has a greatly improved resolubility. The present invention has been accomplished on the basis of the above-described finding. Namely, the present invention relates to a lyophilized preparation comprising dextran and cis-1,1-cyclobutanedicarboxylate(2R)-2-methyl-1,4-butanediamine platinum (II). The present invention further relates to a method for producing the lyophilized preparation which comprises dissolving dextran and cis-1,1-cyclobutanedicarboxylate(2R)-2-methyl-1,4-butanediamine platinum (II) in water to obtain a solution containing 0,1 to 1,4 % of the platinum compound and 0,5 to 2 parts by weight of the dextran per part by weight of the platinum compound, and then lyophilizing the resulting solution. Dextran which can be used in the present invention has a molecular weight of, 40,000 to 150,000, preferably 40,000 to 70,000. The amount of dextran to be added is not less than about 0.2 part by weight, preferably not less than about 0.5 part by weight per part by weight of the platinum compound in order to obtain a sufficient effect in the invention. Although the addition of an excess amount of the additive does not have any adverse effect, it will cause lowering in the efficiency of lyophilization and a container having a large volume must be used for preparation. Accordingly, the practical upper limit is 5 parts by weight, preferably 2 parts by weight per part by weight of the platinum compound. The preparation of the present invention can be produced in the following manner. The platinum compound and dextran are optionally mixed with, conventional excipients, extenders and tonicity agents, The mixture is dissolved in distilled water for injection at a temperature of 15 to 70°C to obtain the solution containing 0.1 - 1.4%, preferably 0.5 - 1.4% of the platinum compound and the resulting solution is made germfree or sterilized. The treated solution is then freezed at a temperature not higher than 0°C, preferably from -10 to -40°C and dried in vacuo at a shelf temperature of -40 to 40°C by a conventional method. Now, the effect of the invention will be illustrated by referring to Experimental Example. Experimental Example 10 ml of distilled water for injection was added to each preparation of Examples 1 to 4 and Referential Examples 1 and 2 which will be described hereinafter. The mixture was shaken and a time taken until the solid was dissolved was measured. The results are shown in the following Table. Preparation Time taken for dissolution Example 1 10 sec " 2 10 sec " 3 15 sec " 4 15 sec Ref. Example 1 5 min " 2 30 min or longer It is apparent from the Table that all of the solids in the preparations (Examples 1 to 4) of the present invention are rapidly dissolved within 15 sec, while the preparation of Referential Example 1 takes 5 min. to dissolve in water and some part of the preparation of Referential Example 2 is left undissolved even after 30 min. Accordingly, the present invention can provide a lyophilized preparation of the platinum compound, which has an improved solubility. Example 1 10 g of the platinum compound and 10 g of Dextran 40 were dissolved in distilled water for injection to a volume of one liter in total. The resulting solution was filtered through a membrane filter to remove germs. 10 ml of the solution was put into each of 20-ml glass vials and lyophilized by a conventional method to obtain a preparation. Example 2 10 g of the platinum compound and 20 g of Dextran 40 were dissolved in distilled water for injection to a volume of one liter in total. The resulting solution was filtered through a membrane filter to remove germs. 10 ml of the solution was put into each of 20-ml glass vials and lyophilized by a conventional method to obtain a preparation. Example 3 10 g of the platinum compound and 5 g of Dextran 70 were dissolved in distilled water for injection to a volume of one liter in total. The resulting solution was filtered through a membrane filter to remove germs. 10 ml of the solution was put into each of 20-ml glass vials and lyophilized by a conventional method to obtain a preparation. Example 4 10 g of the platinum compound and 20 g of Dextran 70 were dissolved in distilled water for injection to a volume of one liter in total. The resulting solution was filtered through a membrane filter to remove germs. 10 ml of the solution was put into each of 20-ml glass vials and lyophilized by a conventional method to obtain a preparation. Referential Example 1 10 g of the platinum compound was dissolved in distilled water for injection to a volume of one liter in total. The resulting solution was filtered through a membrane filter to remove germs. 10 ml of the solution was put into each of 20-ml glass vials and lyophilized by a conventional method to obtain a preparation. Referential Example 2 100 mg of the bulk drug powder of the platinum compound sterilely produced was put into each of 20-ml glass vials to obtain a preparation.

Claims: Claims for the following Contracting States : DE, FR, GB, IT, SE A lyopholized preparation comprising dextran and cis-1,1-cyclobutanedicarboxylate(2R)-2-methyl-1,4-butanediamine platinum (II). The preparation according to Claim 1, wherein the molecular weight of the dextran is 40,000 to 150,000. The preparation according to Claim 1, wherein the amount of dextran to be added is 0.2 part by weight to 5 parts by weight per 1 part by weight of the platinum compound. The preparation according to Claim 1, wherein the amount of the dextran to be added is 0.5 part by weight to 2 parts by weight per 1 part by weight of the platinum compound. A method for producing a lyophilized preparation which comprises dissolving dextran and cis-1,1-cyclobutanedicarboxylate-(2R)-2-methyl-1,4-butanediamine platinum (II) in water to obtain a solution containing 0,1 to 1,4% of the platinum compound and 0,5 to 2 parts by weight of the dextran per part by weight of the platinum compound, and then lyophilizing the resulting solution. Claims for the following Contracting State : ES A method for producing a lyophilized preparation which comprises dissolving dextran and cis-1,1-cyclobutanedicarboxylate(2R)-2-methyl-1,4-butanediamine platinum (II) in water, and then lyophilizing the resulting solution. The method according to Claim 1, wherein the dissolving temperature is 15 to 70°C. The method according to Claim 1, wherein the molecular weight of the dextran is 40,000 to 150,000. The method according to Claim 1, wherein the amount of dextran to be added is 0.2 part by weight to 5 parts by weight per 1 part by weight of the platinum compound. The method according to Claim 1, wherein the amount of the dextran to be added is 0.5 part by weight to 2 parts by weight per 1 part by weight of the platinum compound. The method according to claim 1 which comprises dissolving dextran and cis-1,1-cyclobutanedicarboxylate-(2R)-2-methyl-1,4-butanediamine platinum (II) in water to obtain a solution containing 0,1 to 1,4 % of the-platinum compound and 0,5 to 2 parts by weight of the dextran per part by weight of the platinum compound, and then lyophilizing the resulting solution.

Inventors: OHKUMA, TAKA'AKI, SUZUKI, SHINTARO, YANAGISAWA, NORIAKI
Applicants: NIPPON KAYAKU KABUSHIKI KAISHA
Application year: 1988
Main classification: A61K31
IPC codes: A61K9, A61P35, A61K47, A61K31