DK158564B - PROCEDURE FOR PREPARING A STABLE SOLUTION OF CISPLATIN- (II) DIAMINE DICHLORIDE - Google Patents

Description

in

DK 158564B

The present invention relates to a process for preparing a stable, concentrated solution of cisplatin (II) diamine dichloride called cisplatin in a solvent.

The platinum compounds are a particular group of compounds among the antineoplastic agents. They were first found to have the antibiotic effect of Rosenberg and his colleagues in 1965 [Rosenberg, B. et al.,

Nature (London), 205, 698-699 (1965)], and then found by Rosenberg and his colleagues to be potent antitumor agents in animals [Rosenberg, B. et al., Nature (London), 222, 385-386 (1965). )].

Structurally, they represent a complex formed by a central platinum atom surrounded by various arrangements of chlorine atoms or ammonia groups in either cis or transplanar relation. Two of the more commonly studied platinum compounds are shown below: 15

Cl

Cl NH

C1 3 / —I— - J7 JH,

Cl NH3

Cl 25

Cisplatin (II) Cisplatin (IV)

Di ammi ndi chloride Di ammi ntetrachloride

As can be seen, the compound cisplatin (II) di aminichloride has all its chloro and amino groups in a single plane. This compound, now known by its US official name (USAN) cisplatin, has been synthesized according to the following reaction: nh4ci 35 K2 [PtCl4] + 2NH3- ^ cis- [Pt (NH3) 2Cl2] + 2KC1 [Cf. . Kauffman, G.B. et al., in Inorganic Synthesis, J. Kleinberg (Ed.), pages 239-245, McGraw-Hill Book Co., Inc., New York, 1963],

Breusovia-Baidala, Y.G. et al, discusses in Akademia Nauk SSSR, no.

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6. pages 1239-1242 (June 1974), the slow isomerization of cisplatin (II) diamine dichloride in aqueous solution to the transform.

Reishus, J.W. and Martin, D.S., in the Journal of the American Chemical Society, 83, 2457-2462 (1961), describe the acidic hydrolysis of cisplatin at 25 ° C and 35 ° C. These studies were performed in aqueous solutions at concentrations of 1.5 x 10 ~ 3 M, 2.5 x 10 3 M and 5.0 x 10 ~ 3 M, respectively, corresponding to 0.45, 0.75 and 1, respectively. The authors state that there was some ambiguity in locating the origin (i.e., "zero point") of the hydrolysis curves because the samples require from 10 to 30 10 minutes to completely dissolve, even at these low concentrations.

Rozencweig, M. et al., In Annals of Internal Medicine, 86, 803-812 (1977), report the results of the various preclinical and clinical studies on the use of cisplatin in experimental tumors in animals as well as in different types of human tumors. They state that the drug investigated available to qualified specialists through the National Cancer Institute's Investigational Drug Branch of the National Cancer Institute Program was supplied as a white lyophilized powder in vials containing 10 mg of cisplatin, 90 mg of sodium chloride, 100 mg of mannitol (USP) and hydrochloric acid for pH adjustment. When reconstituted with 10 ml of sterile water for injection (U.S.P), each ml of the resulting solution will contain 1 mg of cisplatin, 10 mg of mannitol and 9 mg of NaCl.

Talley, R. W. et al describe in Cancer Chemotherapy Reports, 25 57, 465-471 (1973) the results of their Phase I clinical study of the use of cisplatin in the treatment of 65 people with a wide variety of neoplasms. As in the previous publication, the drug was supplied to them by The National Cancer Institute in vials containing 10 mg of cisplatin, 90 mg of sodium chloride and 100 mg of mannitol, for 30 reconstitution with 10 ml of sterile water.

Rossof, A.H. et al., in Cancer, 30, 1451-1456 (1972) describe the results of their use of cisplatin in the treatment of 31 people with tumor type variation. They state that the drug supplied by The National Cancer Institute was manufactured by Ben 35 Venue Laboratories, Inc. and per. vials contained 10 mg of cisplatin, 10 mg (sic) mannitol and 9 mg (sic) NaCl, and the yellowish-white powder readily dissolved in 8-10 ml of sterile water.

Certain information regarding cisplatin chemistry and pharmaceutical formulation is given on pages 1-5 and 31-32 of the publication "CLINICAL

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3 BROCHURE, CIS-PLATINUM (II) DIAMINEDICHLORIDE (NSC-119875) ", H. Haldelsman et al., Investigational Drug Branch, Cancer Chemotherapy Evaluation Program, Division of Cancer Treatment, National Cancer Institute (revised August 1974). Pages 31 and 32 therein relates to the formulation of cisplatin for free delivery by the National Cancer Institute to physicians for their clinical assessment in cancer chemotherapy and reads as follows:

PHARMACEUTICAL DATA SHEET

10 NSC-119875 Cis-Diamindichloroplatin (II)

Dose formulation 10 mg / vial: The contents of each 20 ml flint vial appear as a grayish white lyophilized cake. Each vial contains 10 mg of NSC-119875, 90 mg of sodium chloride, 100 mg of mannitol and hydrochloric acid for pH adjustment.

Preparation of Solution 20 10 mg / vial: Upon reconstitution with 10 ml of sterile water for injection, USP, each ml of the resulting solution will contain 1 mg of NSC-119875, 10 mg of mannitol, and 9 mg of sodium chloride with a pH in the range 3.5-4.5. Storage: The dry, unopened vials should be stored at refrigerator temperature (4-8 ° C).

Stability: Intact vials have a provisional stability of 1 year when stored at refrigerator temperature (4-8 ° C). The stability instructions can be adjusted after the completion of a two-year storage study. Reconstitution 30 as recommended results in a pale yellow solution that is stable for a maximum of one hour at room temperature (22 ° C) under exposure to normal room lighting and a maximum of eight hours at room temperature (22 ° C) protected from light. Reconstituted solutions may precipitate after 35 one hour at refrigerator temperature (4-8 ° C).

Warning: The lyophilized dose preparations contain no preservatives and therefore it is recommended to discard solutions eight hours after reconstitution.

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4

August 1974

Clinical Drug Distribution Section Drug Development Branch

British Patent Publication No. 2021946A discloses stable 5 aqueous solutions of cisplatin with a concentration of cisplatin between ca. 0.1 and 1.0 mg / ml and a pH in the range of 2.0 to 3.0. The solutions may also contain a non-toxic, pharmaceutically acceptable inorganic chloride ion source such as sodium chloride and an excipient such as mannitol.

It has now been found that a stable, concentrated solution of cisplatin in a solvent can be prepared by the process of the invention, which is characterized by dissolving a sufficient amount of cisplatin in the solvent to provide a cisplatin concentration of 2.5 to ca. 25 mg / ml, containing 15 solvents from ca. 30% to approx. 95% polyethylene glycol with an average molecular weight of from approx. 150 to approx. 9000 or a methoxypolyethylene glycol having an average molecular weight of about 300 to approx. 6000, or a mixture thereof, and from ca. 5% to approx. 70% water, wherein the solution also contains at least one non-toxic, pharmaceutically acceptable chloride ion source in an amount which is at least approx. equivalent to the amount of cisplatin present in the solution.

Stable aqueous solutions of cisplatin have been described in British Patent Publication No. 2021946A. Although stable solutions 25 containing cisplatin concentrations of up to approx. 1 mg / ml is available in such aqueous media at room temperature, the crystallization of the cis-platinum can occur in the cold at cispiatin concentrations which are significantly above ca. 0.5 mg / ml. Resolution of such crystallized cisplatin is not easily accomplished by shaking at room temperature, although a solution can again be obtained by heating to ca. 37 ° C. Since after-sales shipping and storage temperatures cannot be controlled and crystallization of cisplatin in vials would create an undesirable problem for the practitioner, the maximum practical concentration of cisplatin in such aqueous media is approx. 0.5 mg / ml.

The cispiatin solutions prepared by the process of the present invention may contain up to about 25 mg of cisplatin per ml, although the preferred amount is approx. 15 mg / ml. Solutions prepared by the method of the present invention containing 15 mg of cisplatin per ml. ml has been kept at a temperature of 4 ° C for 12 months

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5 without crystallization of cisplatin. Such solutions have also been frozen down to ca. -60 ° C and then thawed at room temperature with no evidence of cispi atine precipitation. Thus, practical solutions prepared according to the present invention may have cisplatin concentrations that are at least 30 times higher than practical aqueous solutions prepared according to the prior art.

It will be appreciated that the concentrated solutions of cisplatin provided by the present invention result in lower shipping, storage and other costs per unit of time. dose unit in comparison to the known aqueous solutions. Although the known lyophilized solid form also has lower shipping and storage costs, this saving is more than offset by the time and cost involved in lyophilization.

In a preferred embodiment of the method according to the present invention, the dissolution medium comprises from ca. 80% to approx. 95% (and more preferably from about 85% to about 90%) polyethylene glycol having an average molecular weight of about 250 to approx. 1600 (and more preferably from about 250 to about 650) and from about 5% to approx. 20% (and more preferably from about 10% to about 15%) of water. In a most preferred embodiment, the dissolution medium comprises approx. 90% polyethylene glycol with an average molecular weight of from approx. 350 to approx. 450 and approx. 10% water.

Preferably, the solution contains from ca. 5 to approx. 20 mg cisplatin per and most preferably from about 10 to approx. 15 mg / ml. The non-toxic, pharmaceutically preferred chloride ion source is preferably present at a concentration of at least about two equivalents per equivalent of cisplatin in the solution. Concentrations as high as 50 equivalents or more chloride ion per equivalent cisplatin may be used, depending on the cispin concentration, percentage of water present and the particular chloride ion source, but such high chloride ion concentrations are usually neither necessary nor desirable. It will be appreciated by those skilled in the art that with a high cisplatin concentration and a low water content, it would not be possible to dissolve a sufficient amount of chloride ion source, such as sodium chloride, to provide 50 equivalents of chloride ion per liter. equivalent of cisplatin. In addition, a saturated or nearly saturated solution of an inorganic chloride salt would be undesirable due to the possibility of crystallization from the solution in cold. In the above situation, 50 equivalents of chloride ion per equivalent cisplatin is obtained using hydrochloric acid as chloride ion source, but this could give a solution of undesirably high acidity, ie. low pH. It 6

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It has been found that highly acidic solutions are somewhat less stable than more moderately acidic solutions. The pH range of the solutions is preferably from ca. 1.5 to approx. 4.5. It is preferred to use from ca. 2 to approx. 10 equivalents of chloride ion per equivalent to cisplatin, and most preferably from ca. 3 to approx. 7 equivalents of chloride ion per equivalent of cisplatin.

The chloride ion may be provided by the addition of hydrochloric acid, a non-toxic pharmaceutical metal halide such as sodium chloride, potassium chloride, calcium chloride or magnesium chloride, or the hydrochloric acid addition salt of a non-toxic, pharmaceutically acceptable tertiary amine such as triethylamine or mixtures thereof. The preferred chloride ion source is hydrochloric acid, sodium chloride or a mixture thereof.

Polyethylene glycols and methoxypolyethylene glycols have the general formulas, respectively, 15 H (OCH 2 CH It is preferred to use SENTRY grade CARBOWAX® polyethylene glycols which are manufactured to meet U.S.P., N.F. and F.C.C. specifications for food and drug applications. Typical molecular weight ranges for many different CARBOWAX® polyethylene glycols and CARBOWAX® methoxypolyethylene glycols are listed in Tables 1 and 2.

TABLE 1 25 CARBOWAX® Typical polyethylene glycols molecular weight range 200 190 to 210 30 300 285 to 315 400 380 to 420 600 570 to 630 1000 950 to 1050 1540 1300 to 1600 35 4000 3000 to 3700 6000 7000 to 9000 TABLE 2

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7 CARBOWAX® Typical methoxypolyethylene molecular weight range 5 glycol is 350 335 to 365 550 525 to 575 750 715 to 785 10 2000 1850 to 2150

Polyethylene glycols are known to form complexes with certain inorganic salts. Thus, the reaction of polyethylene glycols with ammonium cobalt thiocyanate to form a blue complex base is one colorimetric method for determining the concentration of polyethylene glycols in various mixtures. It is believed that the unique stability of cisplatin in the solutions prepared by the process of the present invention may be due to a complex formed between the cispiatin and the polyethylene glycol, but this is only theory and does not form part of the invention. Evidence of complex formation has been found by thin layer chromatography. Using the techniques described below, aqueous cisplatin produces a spot of approx. Rf 0.65.

However, a solution of cisplatin in 90% polyethylene glycol 400 -25 gives 10% H 2 O (or 10% 0.5 N HCl) a spot of approx. Rf 0.3, which forms stripes to approx. Rf 0.65. Dilution with significant amounts of water apparently breaks the complex immediately, as dilution of the above PEG-H 2 O (or HCl) solution with five volumes of water shows only a cisplatin stain of approx. Rf 0.65.

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Thin! Agskromatografi

Apparatus and reagents (a) TLC plates - EM Laboratories silica gel 60 plates, catalog no. 5763 or equivalent.

(B) Eluent - acetoner / N HNO 3 (9: 1). Made fresh daily.

(c) Developing agent - dissolve 5.6 g of stannous chloride in 10 ml of concentrated HCl. Add 90 ml distilled water and 0.2 g Kl. Mix well. Made fresh daily.

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(d) Set the laboratory oven to 100 ° C.

Procedure (a) The sample is diluted with 5 volumes of dimethyl formamide (DMF) [Burdick and Jackson, distilled in glass].

5 (b) A TLC plate is stained with 5 μΐ of the sample and 5 μΐ of a standard solution containing cisplatin (and transplatin and platinum B, if appropriate) at a concentration approximately the same as expected in the sample to be analyzed. . A height of 10 cm in a TLC tank which is already equilibrated with the eluent is obtained. The dried plate is sprayed with the freshly developed developer solution and placed in a 100 ° C hot oven for ten minutes.

The yellow / purple zones are observed.

(c) Approximate Rf values:.

0.65 - cisplatin 0.76 - transplatin 0.9 - platinum B.

HPLC analyzes of the solutions prepared by the method of the present invention for cispiatin content can be performed according to the method described in British Patent Publication No. 2021946A. The preferred mobile phase is ethyl acetate / methanol / dimethylformamide / distilled water (25/16/5/5).

The standard is preferably cisplatin dissolved in dimethyl formamide at a concentration of 1 mg / ml. Samples for analysis are dissolved with dimethylformamide at an appropriate cispiatin concentration of 1 mg / ml.

Although no particular benefit is obtained from their presence, the solutions prepared by the process of the present invention may, if desired, contain a conventional physiologically acceptable additive such as mannitol.

Based on previous stability studies, the calculated stability of the solutions prepared by the process of the invention (defined as a 10% loss of strength) over two years at room temperature.

In a preferred embodiment of the process of the invention, the solutions are made sterile and pyrogen-free and packed in sterile pyrogen-free containers. Such solutions may then be diluted with, for example, sterile water for injection, U.S.P., or sterile normal saline solution, U.S.P. and administered by intramuscular or intravenous route. Means for sterilizing these solutions are well known in the art.

It is preferred to allow the solutions to pass through a sterile 9

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pyrogen-free 0.22 μ Mill ipore filter, using aseptic techniques, under sterile nitrogen pressure. Millipore is a registered trademark of Millipore Corporation for membrane filters. The sterile filtrate is collected in sterile, pyrogen-free containers and then filled into appropriate sterile, pyrogen-free vials in the desired amount, to be stuffed with sterile, pyrogen-free plugs (preferably Teflon-coated) and sealed with sterile aluminum seals.

For use in the treatment of cancer, the concentrated solutions are diluted to the desired concentration (typically 1 mg of cisplatin 10 per ml) with sterile water for injection, U.S.P., or sterile normal saline solution, U.S.P. or sterile glucose solution and is used for intramuscular or intravenous injection, or intravenous infusion as with known cisplatin preparations. Currently used doses of mild to moderately acceptable toxicity are in the range of 60-100 mg / m intravenously as a single dose or divided over 3-5 days to be repeated at four-week intervals. A dosage of 60 mg / m is roughly equal to 1.5 mg / kg, which again corresponds roughly to 105 mg / patient weighing 70 kg.

Often, concomitant therapy with other chemotherapeutic agents is used to obtain the best results.

As used above and in the claims, the references to "equivalents" mean chloride ion per liter. "equivalent" cisplatin molar equivalents. Thus, for example, when using the preferred range from about 3 to approx. 7 equivalents of chloride ion per equivalent cisplatin, one will use from approx. 3 to approx. 7 moles of NaCl per mole of cisplatin, but from 1.5 to approx. 3.5 moles of CaCl mol of cisplatin.

Platinum B is an arbitrary name used here for an acidic reaction product of cisplatin, which is one half of the known Magnus red complex and has been experimentally assigned the following structure: 30 - Cl® ®.ϊί® / C1 4 \ // Pt \ 35 L_3 _

DK 158564B

The invention is illustrated by the following examples.

Example 1

Stable, concentrated solution of cisplatin (10 mg / ml) in 90% polyethylene glycol 400 - 10% IN HCl

Cisplatin (500 mg) was slurried in a solution of 5 ml of 1N HCl and 45 ml of polyethylene glycol 400. After 2.5 days of stirring at room temperature (with the container protected from light with aluminum foil) a clear yellow solution was obtained. Portions of the solution were placed in 17 ml amber cap-glass vials, clogged with Teflon-coated plugs, sealed with aluminum capsules and placed for storage stability experiments at various temperatures. After two weeks of storage at 45 ° C, thin layer chromatography (TLC) showed the presence of a trace of transplatin and ca. After two weeks of storage at 56 ° C, TLC showed the presence of <1% transplatin and ca.

15 3% platinum B. Samples stored for two weeks at 56 ° C were diluted with 4, 9 and 19 volumes of water to obtain clear solutions containing 2, 1 and 0.5 mg / ml cisplatin, respectively. A slight haze developed in each of the diluted samples after standing ca. 18 hours at room temperature.

20

Example 2

Stable, concentrated solution of cisplatin (10 mg / ml) in 90% polyethyl englycol 400 - 10% 0.5N HCl 5 ml of purified water U.S.P. and 5.0 ml of 1 N HCl were mixed and 90.0 ml of polyethylene glycol 400 were added. To 50 ml of the above solution was added 500 mg of cisplatin and the mixture was protected from light with aluminum foil and stirred at room temperature for 24 hours until a clear solution was obtained. TLC of the freshly prepared solution showed only one cisplatin zone with a possible trace of transplatin. 2 ml portions 30 of the solution were placed in 17 ml amber vials, clogged with Teflon coated plugs, sealed with aluminum capsules and placed for storage stability experiments at various temperatures. A sample cap glass was frozen in a dry ice-acetone bath for one hour and allowed to stand at room temperature. A clear solution was obtained without evidence of precipitation. After 35 three months of storage at both 37 ° C and 45 ° C, TLC showed the presence of 1-2% platinum B and a possible trace of transplatin. After one month of storage at 56 ° C, TLC showed the presence of more than 5% but less than 10% platinum B and a trace of transplatin. Samples stored at 37 ° C and 45 ° C for three months and at 56 ° C for one month were diluted with four volumes of purified water U.S.P.

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π to obtain clear solutions containing 2 mg / ml cisplatin. The diluted solutions remained clear after 24 hours at room temperature.

Example 3

Stable, concentrated solution of cisplatin (10 mg / ml) plus CaCU (20 mg / ml) in 90% polyethylene glycol 400 - 10¾ 0.5N HCl 2 g of reagent classified anhydrous CaClg was dissolved in a mixture of 5 ml of purified water U.S.P. and 5 ml of 1N HCl. Polyethylene glycol 400 (89 ml) 10 was added to bring the volume to 100 ml. To 50 ml of this solution was added 550 mg of cisplatin and the mixture was protected from light with aluminum foil and stirred at room temperature for 24 hours until a clear solution was obtained. TLC of the freshly prepared solution showed only one cispi atin zone with a possible trace of transplatin. 2 ml portions of the solution were placed in 17 ml amber vials, clogged with Teflon-coated plugs, sealed with aluminum capsules and placed for storage stability experiments at various temperatures. A sample vial was placed in a dry ice-acetone bath for 0.5 hour and frozen to a clear gel. It was then allowed to stand at room temperature and a clear solution obtained. After three months of storage at 37 ° C, TLC showed the presence of ca. 1-2% platinum B and a possible trace of transplatin. After three months of storage at 45 ° C, TLC showed the presence of ca. 5% platinum B and a possible trace of transplatin. After one month of storage at 56 ° C, TLC showed the presence of 8-10% platinum B and a trace of transplatin. Samples stored at 37 ° C and 45 ° C for three months and at 56 ° C for one month were diluted with four volumes of purified water U.S.P. to obtain clear solutions containing 2 mg / ml cisplatin. The diluted solutions remained clear after 24 hours at room temperature.

Example 4

Stable, concentrated solution of cisplatin (approx. 22 mg / ml) plus CaClp (25 mg / ml) in 90% polyethylene glycol - 10% 0.5N HCl

To 3 ml of a solution of 90% polyethylene glycol 400 and 10% 0.5N HCl was added 45 mg of cisplatin and the mixture was stirred for approx. 1 hour at room temperature until a clear solution was obtained. An additional 30 mg of cisplatin (25 mg / ml in total) was added and the mixture was stirred at ca.

45 ° C for one hour and then at room temperature for 18 hours to produce a nearly complete solution. The small amount of insoluble material was removed by filtration. The TLC of the filtrate showed only one

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12 material was removed by filtration. The TLC of the filtrate showed only one cisplatin zone with a possible trace of transplatin. The rest of the solution was placed in a 17 ml amber vial, clogged with a teflon bell-like plug, sealed with an aluminum capsule and kept at 45 ° C for three 5 months. After three months of storage at 45 ° C, TLC showed the presence of ca. 1-2% platinum B and no transplatin. Dilution of the stored solution with purified water U.S.P. to a concentration of 2 mg / ml cisplatin gave clear solutions after standing at room temperature for 24 hours.

10

Example 5

Stable, concentrated solution of cisplatin (Approx. 12 mg / ml) plus NaCl (10 mg / ml) in 90% polyethylene glycol 400 - 10% 0.5N HCl

Sodium chloride (100 mg) was dissolved in a solution of 5 ml of purified water 15 U.S.P. and 5 ml of 1N HCl. To this solution was added 90 ml of polyethylene glycol 400 and the mixture was stirred for 15 minutes. To 50 ml of the latter solution was added 500 mg of cisplatin and the mixture was stirred in the dark at room temperature for three days to obtain a clear solution.

TLC of the freshly prepared solution showed only one cisplatin spot. High-performance liquid chromatographic analysis (HPLC) of the freshly prepared solution showed that it contained 12 mg of cisplatin per ml. ml. Servings are sealed in 17 ml amber vials as described in Example 3 and added to storage stability experiments at various temperatures. After three months of storage at 37 ° C, TLC showed the presence of less than 1% platinum B 25 and no transplatin. After storage at 56 ° C for one month, TLC showed the presence of 1-2% platinum B and no transplatin. Dilution of the Stored Samples with Purified Water U.S.P. to a concentration of 2 mg / ml cisplatin gave clear solutions which remained clear after standing at room temperature for 24 hours.

Thirty HPLC analyzes of samples stored for 3 months at 45 ° C, for 6 months at 37 ° C, and for 8 months at room temperature, showed strength losses, respectively. 6.6%, 6.1% and 2.3%.

Example 6 Stable, concentrated solution of cisplatin (11.4 mg / ml) plus NaCl (10 mg / ml) in 90% polyethylene glycol 400 - 10% water

To a solution of 50 mg of NaCl in 5 ml of purified water U.S.P. and 45 ml of polyethylene glycol 400 were added 500 mg of cisplatin and the mixture was stirred in the dark at room temperature for 6 hours to give a clear solution.

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13 ning. TLC of the freshly prepared solution showed only one cispiatin stain; HPLC analysis showed that it contained 11.4 mg of cisplatin per ml. ml. Servings were sealed in 17 ml amber vials as described in Example 3 and added to storage stability experiments at various temperatures. After 5 three months of storage at 37 ° C and 45 ° C, TLG showed the presence of 1% platinum B and no transplatin. After storage at 56 ° C for one month, TLC showed the presence of 2-3% platinum B and no transplatin. Dilution of the Stored Samples with Purified Water U.S.P. to a concentration of 2 mg / ml cisplatin gave clear solutions which remained clear after standing at 10 room temperature for 24 hours.

HPLC analyzes of samples stored for 3 months at 45 ° C, for 6 months at 37 ° C, and for 7 months at room temperature, showed strength losses, respectively. 6.1%, 7.0% and 0.9%.

Example 7

Stable, concentrated solution of cisplatin (10 mg / ml) in 90% polyethylene glycol 600 - 10% 0.5N HCl

To a solution of 2.5 ml of purified water U.S.P., 2.5 ml of 1N HCl and 45 ml of polyethylene glycol 600 was added 500 mg of cisplatin and the mixture was stirred in the dark at room temperature for 5 hours to give a clear solution. TLC of the freshly prepared solution showed only one cispiatin stain.

Samples of the freshly prepared solution were diluted with 1, 2, 3, 4, 5 and 9 volumes of purified water U.S.P .; these dilute solutions showed no crystallization after 16 hours standing at room temperature or 25 ° C. Portions of the freshly prepared solution were sealed in 17 ml amber vials as described in Example 3 and added to storage stability experiments at various temperatures. After three months of storage at 37 ° C and 45 ° C for 3 months, TLC showed the presence of 1% platinum B and no transplatin. After storage at 56 ° C for one month, TLC showed the presence of 3.4% platinum B and no transplatin. Dilution of the Stored Samples with Purified Water U.S.P. to a concentration of 2 mg / ml cisplatin gave clear solutions which remained clear after standing at room temperature for 24 hours.

Example 8

Stable, concentrated solution of cisplatin (10 mg / ml) plus NaCl (10 mg / ml) in 90% polyethylene glycol 400 - 10% 0.2N HCl

To a solution of 0.5 mg of NaCl in 4 ml of purified water U.S.P., 1 ml of 1N HCl and 45 ml of polyethylene glycol 400 was added 250 mg of cisplatin and mixed.

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gene was stirred in the dark at room temperature for 4 hours to give a clear yellow solution. TLC of the freshly prepared solution showed only one cisplatin spot. Dilutions of the freshly prepared solution with 1, 2, 3, 4, 5 and 9 volumes of purified water U.S.P. gave clear solutions which 5 remained clear after 24 hours standing at room temperature. The 1-, 2-, 3-, 4- and 5-volume dilutions showed no crystallization when stored at 4 ° C for 24 hours. Portions of the freshly prepared solution were sealed in 17 ml amber vials as described in Example 3 and added to storage stability experiments at various temperatures.

10 After storage at 37 ° C for 3 months, TLC showed the presence of 1% platinum B with a possible trace of transplatin. After storage at 45 ° C for 3 months, TLC showed the presence of 5% platinum B with a possible trace of transplatin.

After storage at 56 ° C for one month, TLC showed the presence of 2-3% platinum B and no transplatin. Dilution of the Stored Samples with Purified Water 15 U.S.P. to a concentration of 2 mg / ml cisplatin gave clear solutions which remained clear after standing at room temperature for 24 hours.

Example 9

Stable, concentrated solution of cisplatin (2.5 mg / ml), NaCl (9 mg / ml) 20 and mannitol (12.5 mg / ml) in acidic 31% (w / v) aqueous polyethylene glycol 6000

Sodium chloride (0.9 g), mannitol (1.25 g) and polyethylene glycol 6000 31.3 g) were dissolved in sufficiently purified water U.S.P. to give 100 ml of solution and the solution was acidified to a pH of 2.2 with 1N HCl (0.7 ml). Cisplatin (255 mg) was added and the mixture was stirred in the dark at room temperature for 3 days to give a clear solution. The TLC of the freshly prepared solution showed only one c in splatin zone. Aliquots of the freshly prepared solution were sealed in 17 ml amber vials as described in Example 3 and added to storage stability experiments at 45 ° C and 56 ° C. After storage for two months at 45 ° C and 56 ° C, TLC showed less than 1% platinum B and no transplatin. Dilution of the stored samples with a corresponding volume of purified water U.S.P. gave clear solutions which remained clear after standing at room temperature for 24 hours.

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Example 10

Stable, concentrated solution of cisplatin (15.8 mg / ml) plus NaCl (10 mg / ml) in 90% aqueous polyethylene glycol 400

Polyethylene glycol 400 (90 ml) was dissolved in a solution of 1.0 g of NaCl 5 in 10 ml of purified water U.S.P. To 60 ml of the resulting solution was added 900 mg of cisplatin and the mixture was stirred in the dark at room temperature for five hours to obtain a clear solution. TLC of the freshly prepared solution showed only one cispi atin zone; HPLC analysis showed that it contained 15.8 mg of cisplatin per ml. ml. Dilution of the freshly prepared solution with four volumes of purified water U.S.P. gave a clear solution which remained clear after 24 hours standing at room temperature. Portions of the free prepared solution were sealed in 17 ml amber vials as described in Example 3 and added to storage stability tests at various temperatures. After two months of storage at 45 ° C, TLC showed 1.5% platinum B and no transplatin. After one month of storage at 56 ° C, TLC showed 2% platinum B and no transplatin. The sample stored at 56 ° C was diluted to a concentration of 2 mg / ml with sterile water for injection and the sample stored at 45 ° C to concentrations of 2.5 and 5.0 mg / ml cisplatin with sterile water for injection. . The 20 all provided clear solutions which remained clear after standing at room temperature for 24 hours.

HPLC analysis of samples stored for 3 months at 45 ° C, for 6 months at 37 ° C, and for 8 months at room temperature, showed strength losses, respectively. 7.6%, 7.6% and 0%.

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Example 11

Stable, concentrated solution of cisplatin (15 mg / ml) plus CaCU (25 mg / ml) in 90% aqueous polyethylene glycol 400

To a solution of 2.5 g CaClg in 10 ml of purified water U.S.P. 30 ml of polyethylene glycol 400 were added and the resulting solution was stirred for ten minutes. To 50 ml of the above solution was added 750 ml of cisplatin and the mixture was stirred for five hours in the dark at room temperature for 6 hours to give a clear solution. TLC of the freshly prepared solution showed only one cisplatin zone. Dilutions of the freshly prepared solution, respectively. 1, 2, 5 and 10 volumes of purified water U.S.P. gave clear solutions. Aliquots of the freshly prepared solution were sealed in 17 ml amber vials as described in Example 3 and added to storage stability experiments at 45 ° C and 56 ° C. After storage for two months at 45 ° C and 56 ° C, TLC showed the presence of 1.5% platinum B and no transplatin.

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16

After one month of storage at 56 ° C, TLC showed 2.5-5% platinum B and no transplatin. The sample stored at 56 ° C was diluted to a concentration of 2 mg / ml and the sample stored at 45 ° C was diluted to concentrations of 2.5 and 5.0 mg / ml of cisplatin with sterile water for injection. They formed all clear solutions which remained clear after standing at room temperature for 24 hours.

Example 12

Sterile, stable, concentrated solution of cisplatin in 90% aqueous polyethylene glycol 400 - 10% 0.5N HCl (Label requirement is 15 mg / ml cisplatin activity) NOTE: Cisplatin is a possible carcinogen. Protective clothing, gloves, masks, goggles and headgear must be worn throughout the procedure. All work areas and equipment must be completely cleaned to avoid future infections.

RULE

per. ml per 10.0 ml Cisplatin 0.015 g 0.150 g

Sodium chloride 0.015 g 0.150 g 0.5N hydrochloric acid 0.10 ml 1.0 ml

Polyethylene glycol 400 (SENTRY grade) q.s. to 1.0 ml.q.s. to 10.0 ml 25 ^ This cispiatin weight requires a strength of 1000 µg / mg. To determine the required amount of cispiatin, the following formula is used: 1000 x 0.015 g of cisplatin potency in p / mg = 9 ™ "Necessary c1sPlat1" 30 µl liter of 0.5N hydrochloric acid is prepared as follows: place in a clean 1-liter Erlenmeyer flask.

2. With rapid stirring, 42.75 ml of concentrated hydrochloric acid 35 is added slowly and carefully. Stir for ten minutes. Close with a clean butyl rubber stopper.

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PREPARATION INSTRUCTIONS FOR 1 LITER STERILE SOLUTION

1. Place 100 ml of 0.5 N hydrochloric acid in a clean calibrated 1-1 ter Erlen-meyer flask containing a suitable stirrer, such as a 6 cm magnetic 5 Teflon-coated stir bar.

2. Add, under moderate stirring, 15.0 g of sodium chloride. Stir until the salt is completely dissolved.

3. Add, with rapid stirring, 750 ml of polyethylene glycol 400 (SENTRY grade) and stir for 5 minutes.

4. Remove the magnetic stir bar and return the supplied liquid to the flask.

15 5. Carefully add 15.0 g of cisplatin activity.

6. Add polyethylene glycol 400 (SENTRY grade) to the 1-liter mark (a total of 880 ml polyethylene glycol 400 is required).

20 7. Place the tefon stirrer again in the mixture and close with a clean butyl rubber stopper.

8. Wrap the flask in aluminum foil to exclude all light.

25 9. Stir quickly for 24-48 hours at ambient temperature. A clear solution must be obtained. If no clear solution is obtained within 48 hours, the mixture may be heated to 37-40 ° C for 2-6 hours in the absence of air and light to accelerate rapid dissolution of the remaining cisplatin. Cool to 23-27 ° C.

10. Using aseptic technique, the dark yellow solution is passed under a suitable sterile nitrogen pressure through a suitable sterile pyrogen-free 0.22 β Millipore filter. Collect the sterile filtrate in a sterile, pyrogen-free Erlenmeyer flask. Close with a sterile butyl rubber stopper.

35 The solution can be stored in the dark.

11. Fill the required amount of sterile solution on sterile pyrogen-free amber vials. Close with sterile pyrogen-free teflon plug. Seal with sterile aluminum seals.

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18 12. The vials should contain the following warning label: NOT FOR DIRECT INTRAMUSCULAR OR INTRAVENOUS USES * * The PEG-400 solution may be diluted with 14 parts of sterile 5 water for injection, USP, or sterile normal saline solution, USP, to form 1 mg / ml of cispi atine solution.

If higher concentrations are needed, relatively less sterile water or saline may be used.

The diluted solutions can be used intravenously or are stable at room temperature (22-26 ° C) for at least 48 hours.

Do not freeze diluted solutions as crystals can form.

13. Keep the vials in the dark.

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Example 13

Stable, concentrated solution of cisplatin (2.5 mg / ml), NaCl (9 mg / ml),

CaCl 3 (15 mg / ml) and mannitol (10 mg / ml) in acidic 31% aqueous polyethylene glycol 400 Sodium chloride (0.9 g), CaClg (1.5 g) and mannitol (1.0 g) were dissolved in a mixture of 31.25 g of polyethylene glycol 400 and 40 ml of purified water USP The solution was acidified to a pH of 2.2 with 1N HCl (0.4 ml), 255 mg of cisplatin was added, and the volume was brought to 100 ml with purified water USP, and the mixture was stirred for five hours in the dark at room-25. temperature to produce a clear solution. TLC of the freshly prepared solution showed only one cispi atin zone.

Example 14

The general procedure of Example 5 is repeated except 30 that the sodium chloride used therein is replaced by a corresponding amount of magnesium chloride and a stable concentrated solution of cisplatin is thereby prepared.

Example 15 The general procedure of Example 5 is repeated except that the sodium chloride used therein is replaced by a corresponding amount of triethylamine hydrochloride and a stable concentrated solution of cisplatin is prepared.

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Example 16

The general procedure of Example 5 is repeated except that the polyethylene glycol 400 used therein is replaced by a corresponding amount of polyethylene glycol 200 and 300, respectively, and stable 5 concentrated cisplatin solutions are prepared.

Example 17

The general procedure of Example 9 is repeated except that the polyethylene glycol 6000 used therein is replaced by a corresponding amount of polyethylene glycol 1000 and 4000, respectively, and stable concentrated solutions of cisplatin are prepared.

Claims (7)

A process for preparing a stable, concentrated solution of cisplatin (II) diamine dichloride called cisplatin in a solvent, characterized in that a sufficient amount of cisplatin is dissolved in the solvent to provide a cisplatin concentration of 2.5 to ca. 25 mg / ml, which solvent contains from approx. 30% to approx. 95% polyethylene glycol with an average molecular weight of from approx. 150 to approx. 9000 or a methoxypolyethylene glycol having an average molecular weight of about 300 to approx. 6000, or a mixture 10 thereof, and from ca. 5% to approx. 70% water, wherein the solution also contains at least one non-toxic, pharmaceutically acceptable chloride ion source in an amount which is at least approx. equivalent to the amount of cisplatin present in the solution. Process according to claim 1, characterized in that the solvent comprises from ca. 80% to approx. 95% polyethylene glycol with an average molecular weight of from approx. 250 to approx. 1600 or a methoxypolyethylene glycol having an average molecular weight of about 300 to 800 or a mixture thereof, and from ca. 5% to approx. 20% water, the solution also containing at least one non-toxic, pharmaceutically acceptable chloride ion source in an amount in the range of about 20%. two to approx. ten equivalents per equivalent of cisplatin in the solution, and the solution containing from ca. 5 to approx. 20 mg cisplatin per ml. 3. A process according to claim 1, characterized in that the non-toxic, pharmaceutically acceptable chloride ion source is hydrochloric acid, sodium chloride, calcium chloride, magnesium choride or triethylamine hydrochloride or a mixture thereof. A process according to claim 1, characterized in that the solvent comprises from ca. 85% to approx. 90% polyethylene glycol with an average molecular weight of from approx. 250 to approx. 650 and from approx. 10% to approx. 15% water, which solution also contains a chloride ion source selected from hydrochloric acid, sodium chloride and mixtures thereof, in an amount which is in the range of approx. three to approx. seven equivalents per equivalent of cisplatin in the solution, and the solution having a cisplatin concentration of from approx. 10 to approx. 15 mg / ml. 5. A process according to claim 4, characterized in that the solution is sterile and sealed in a container such as a vial. Process according to claim 5, characterized in that the solution contains from 10-15 mg of cisplatin per ml. ml and from approx. 10 to approx. 15 mg NaCl ml in a solvent consisting of ca. 90% polyethylene glycol with an average molecular weight of from 350 to approx. 450 and approx. 10% water. Process according to claim 5, characterized in that the solution contains from 10-15 mg of cisplatin per ml. ml and from approx. 10 to approx. 15 mg 5 NaCl per ml in a solvent consisting of ca. 90% polyethylene glycol with an average molecular weight of from 350 to approx. 450 and approx. 10% dilute hydrochloric acid with a concentration of up to approx. 0.5 N. 10 15 20