CH647481A5 - STABLE CONCENTRATED SOLUTIONS OF CISPLASTINE IN A SOLVENT. - Google Patents

Description

The present invention relates to stable and concentrated solutions of cisplatin in polyethylene glycol, aqueous methoxypolyethylene glycol or mixtures thereof, containing a source of chloride ions.

Platinum compounds are a unique group of compounds in the group of an antineoplastic genus. Rosenberg et al., In 1965 [Rosenberg, B. et al., "Nature" (London), 205, pp. 698-699 (1965)], first noticed that they have an antibiotic effect, then that they constitute powerful antitumor agents in animals [Rosenberg, B., et al., “Nature” (London), 222, pp. 385-386 (1969)].

From a structural point of view, these are complexes formed by a central platinum atom, surrounded by various arrangements of chlorine atoms or ammonia groups in either eis or trans position relative to the plane. Two of the most commonly studied platinum compounds are represented by the following diagrams:

Cl

Cl

Cisplatin- (II) - Cisplatin- (IV) -

diaminedichloride diaminetetrachloride

As can be seen, the compound cisplatin- (II) -diamine-dichloride has all of these chloro and amino groups in one plane. This compound, now known as cisplatin according to the terminology of the United States Adopted Name (USAN), was synthesized according to the following reaction:

K2 [PtCl4] + 2NH3 NH * C1 ► cis- [Pt (NH3) Cl2] + 2KC1

[see Kaulfman, G.B. et al., in “Inorganic Synthesis”, J. Kreinberg (Ed.), pp. 239-245, McGraw-Hill Book Co., Inc., New York, 1963].

Y.G. Breusova-Baidala et al., In "Akademia Nauk",

U.R.S.S., N ° 6, pp. 1239-1242 (June 1974) describe the slow isomerization in aqueous medium of cis- (II) -diaminedichloride in trans form.

J.W. Reishus and D.S. Martin, in the "Journal of the American Chemical Society", 83, pp. 2457-1462 (1961), indicate the acid hydrolysis of cisplatin at 25 and 35 ° C. These studies in aqueous solutions at concentrations of 1.5 x 10_3M, 2.5 x 10 ~ 3Mand 5.0 x 10 ~ 3M , which corresponds to 0.45,0.75 and 1.5 mg / ml respectively. The authors indicate that there is a certain ambiguity in the location of the origin (that is to say the zero point), for the hydrolysis curves, because it takes 10 to 30 min for the the sample dissolves completely, even at these low concentrations.

M. Rozencweig et al., In "Annals of Internai Medicine", 86, pp. 803-812 (1977), review the results of various preclinical and clinical studies involving the use of cisplatin in experimental tumors in animals, as well as in various types of human tumors. It should be noted that the study medication, available to qualified researchers through the Investigational Drug Branch of the Cancer Therapy Evalution Program of the National Cancer Institute, is supplied as white lyophilized powder in vials containing 10 mg of cisplatin, 90 mg sodium chloride, 100 mg manni-tol (USP) and hydrochloric acid to adjust the pH. When the product is reconstituted with 10 ml of sterile water for injection (U.S.P.), each milliliter of the resulting solution should contain 1 mg of cisplatin, 10 mg of mannitol and 9 mg of NaCl.

R.W. Talley et al., In "Cancer Chemotherapy Reports", 57, pp. 465-471 (1973), describe the results obtained in phase I of their clinical study concerning the use of cisplatin in the treatment of 65 human patients with a variety of neoplasms. As in the previous publication, the drug is 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, so as to be able to reconstitute the product with 10 ml of sterile water.

A.H. Rossof et al., In "Cancer", 30, pp. 1451-1456 (1972), describe the results obtained by using cisplatin to treat 31 human patients with a whole range of tumors. They note that the drug supplied by the National Cancer Institute is manufactured by Ben Venue Laboratories, Inc. and contains, per vial, 10 mg of

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cisplatin, 10 mg of mannitol and 9 mg of NaCl, and that the yellowish white powder dissolves easily in 8 to 10 ml of sterile water.

Certain information concerning the chemistry and pharmaceutical formulation of cisplatin is provided on pages 1 to 5 and 31 to 32 of the publication entitled "Clinical brochure, cisplatinum- (II) -Diaminedichloride (NSC-119875)", H. Haldelsmann et al ., "Investi-gational Drug Branch, Cancer Chemotherapy Evaluation Program, Division of Cancer Treatment, National Cancer Institute" (edition revised in August 1974). On pages 31 and 32 thereof concerning the formulation of cisplatin supplied free of charge by the N.C.I. for clinicians to carry out their clinical evaluation in cancer chemotherapy, the following indications are noted:

Pharmaceutical data sheet NSC-119875 - Cisplatin- (II) -diaminedichloride Dose formulation

10 mg / vial: The content of each 20 ml lead glass vial looks like a white freeze-dried cake. Each vial contains 10 mg of NSC-119875, 90 mg of sodium chloride, 100 mg of mannitol and hydrochloric acid to adjust the pH.

Preparation of the solution

10 mg / vial: When the product is reconstituted with 10 mg of sterile water for injection, USP, each milliliter of the resulting solution contains 1 mg of NSC-119875, 10 mg of mannitol and 9 mg of sodium chloride having a pH between 3.5 and 4.5.

Storage

Unopened dry vials should be stored at refrigeration temperatures (4 to 8 ° C).

Stability

Intact vials have temporary stability of one year when stored at refrigeration temperature (4 to 8 ° C). Stability recommendations can be adjusted pending the completion of a two-year shelf life study.

The reconstitution carried out as indicated provides a pale yellow solution which is stable for a maximum of 1 h at room temperature (22 ° C) when exposed to normal ambient lighting, and a maximum of 8 h at room temperature. ambient (22 ° C) when protected from light. The reconstituted solutions can form a precipitate, after 1 h, at the refrigeration temperature (4 to 8 ° C).

Precaution

The lyophilized dose formulations do not contain any preservatives and it is therefore desirable to reject the solutions 8 h after having reconstituted them.

British Patent No. 2021946A describes stable aqueous solutions of cisplatin having a concentration of cisplatin between about 0.1 and 1.0 mg / ml and a pH between 2.0 and 3.0. The solutions may also contain a source of mineral chloride ions, pharmaceutically acceptable and non-toxic, such as sodium chloride, and an excipient such as mannitol.

The present invention relates to concentrated stable solutions of cisplatin having concentrations of between about 2.5 and 25 mg / ml. More particularly, the present invention relates to stable concentrated solutions of cisplatin in a solvent medium comprising 30 to 95% by weight of polyethylene glycol, having an average molecular weight of between 150 and 9000, or else a methoxypolyethylene glycol having an average molecular weight of between 300 and 6000, or a mixture thereof, and 5 to 70% by weight of water, these solutions also containing at least one source of pharmaceutically acceptable and non-toxic chloride ions, in an amount which is at less equivalent to the amount of cisplatin present in the solution, and these solutions having a cisplatin concentration of between 2.5 and 25 mg / ml.

Stable aqueous solutions of cisplatin have been described in British Patent Publication No. 2021946A. Although stable solutions containing concentrations of cisplatin up to approximately 1 mg / ml can be obtained in such an aqueous medium at room temperature, crystallization of cisplatin may occur when cold, for concentrations of cisplatin significantly above approximately 0 , 5 mg / ml. It is not easy to redissolve this crystallized cisplatin by shaking the system at room temperature, although a solution can be obtained again by heating to about 37 ° C. As the transport and storage temperatures after sale do not cannot be controlled, and that crystallization of cisplatin in the vials would cause undesirable problems for the physician using it, the maximum practical concentration of cisplatin in such aqueous media is approximately 0.5 mg / ml.

The cisplatin solutions according to the invention can contain up to 25 mg of cisplatin per milliliter, although the preferred maximum is about 15 mg / ml. The solutions according to the invention containing 15 mg of cisplatin per milliliter were maintained at a temperature of 4 ° C for 12 months without any crystallization of cisplatin being observed. Such solutions were also frozen at -60 ° C, then thawed at room temperature without any precipitation of cisplatin observed. Thus, practical solutions according to the invention can offer concentrations of cisplatin at least 30 times higher than those which can have practical aqueous solutions prepared according to the prior art.

It will be noted that the concentrated solutions of cisplatin provided according to the present invention entail lower transport, storage and other costs per unit dose than those involved for the known aqueous solutions. Although the known lyophilized solid form requires lower transportation and storage costs, this saving is more than offset by the time and expense involved in lyophilization.

According to a preferred aspect of the present invention, the solvent medium comprises 80 to 95% by weight (and more preferably,

about 85 to 90%) of polyethylene glycol having an average molecular weight of between 250 and 1600 (and more particularly between 250 and 650) and 5 to 20% (and more preferably 10 to 15%) of water.

According to an even more advantageous aspect of the invention, the solvent medium by weight comprises approximately 90% of polyethylene glycol, having an average molecular weight of between 350 and 450, and approximately 10% of water.

It is preferable that the solution contains 5 to 20 mg of cisplatin per milliliter, and even more advantageously 10 to 15 mg / ml. The non-toxic and pharmaceutically acceptable source of chloride ions is preferably present at the concentration of at least 2 Eq / Eq of cisplatin in the solution. Concentrations as high as 50 Eq or more of chloride ions per equivalent of cisplatin may be used, depending on the concentration of cisplatin, the percentage of water present and the particular source of chloride ions, but concentrations as high chloride ions are generally neither necessary nor desirable.

It will be appreciated by those skilled in the art that in the case of a high concentration of cisplatin and a low water content, it would not be possible to dissolve a sufficient amount of source of chloride ions such as sodium chloride to provide 50 Eq of chloride ions per equivalent of cisplatin. In addition, a saturated or substantially saturated solution of a mineral chloride would be undesirable since it may crystallize in the solution when it is cold.

In the situation described above, 50 Eq of chloride ions per equivalent of cisplatin could be obtained using hydrochloric acid as a source of chloride ions, but this could give a solution having a much too high acidity, that is to say a low pH.

Excessively acidic solutions have been found to be somewhat less stable than more moderately acidic solutions. The pH range of the solutions is preferably understood

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between 1.5 and 4.5. It is preferred to use 2 to 10 Eq of chloride ions per equivalent of cisplatin, and more preferably 3 to 7 Eq of chloride ions per equivalent of cisplatin.

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

The polyethylene glycols and methoxypolyethylene glycols respectively have the following general formulas:

H (OCH2CH2) nOH and CH3 (OCH2CH2) nOCH3

and are commercially available under the names of polyethylene glycols Carbowax and methoxypolyethylene glycols Carbo-wax. It is preferred to use the Sentry grades of Carbowax polyethylene glycols, which are produced to meet U.S.P., N.F. and F.C.C specifications for food and drug applications. Typical molecular weight ranges for a variety of Carbowax polyethylene glycols and Carbowax methoxypolyethylene glycols are provided in Tables I and II.

Table I

Polyethylene glycols

Typical range

Molecular Weight Carbowax

200

190 to 210

300

285 to 315

400

380 to 420

600

570 to 630

1000

950 to 1050

1540

1300 to 1600

4000

3000 to 3700

6000

7000 to 9000

Table II

Methoxypolyethylene

Typical Carbowax glycol range of molecular weights

350

335 to 365

550

525 to 575

750

715 to 785

2000

1850 to 2150

It is known that polyethylene glycols form complexes with certain mineral salts. Thus, the reaction of polyethylene glycols with ammonium cobalt thiocyanate forming a blue complex constitutes the basis of a colorimetric method for determining the concentration of polyethylene glycols in various mixtures. It is believed that the unique stability of cisplatin in solutions according to the invention may be due to a complex formed between cisplatin and polyethylene glycol, but this is theoretical and does not constitute an element of the invention. Evidence for complex formation was not noted in thin layer chromatography.

Using the techniques described below, the aqueous cisplatin produces a spot for an Rf value of approximately 0.65. However, a solution of cisplatin in 90% by weight of polyethylene glycol 400/10% by weight of water (or 10% by weight of 0.5N HCl) provides a spot for an Rf of approximately 0.3 which is spreads out to an Rf of about 0.65. Dilution with large quantities of water seems to immediately break the complex, since dilution of the above solution of PEG-H20 (or HCl) with five volumes of water then only shows a spot corresponding to cisplatin for an Rf d 'about 0.65.

Thin layer chromatography (TLC)

Apparatus and reagents a) TLC plates: 60 silica gel plates from EM Laboratories, Catalog No. 5753, or equivalent.

b) Eluent - acetone: Normal nitric acid (9/1). Prepared fresh daily.

c) Developer: dissolve 5.6 g of stannous chloride in 10 ml of concentrated hydrochloric acid. Add 90 ml of ditilled water and 0.2 g of potassium iodide. Shake well. Prepare a fresh product every day.

d) Laboratory oven set at 100 ° C.

Procedure a) The sample is diluted with 5 volumes of dimethylformamide (DMF) (from Burdick and Jackson, and distilled in glass).

b) A TLC plate is stained with 5 days of the sample and 5 μl of a standard solution containing cisplatin (and transplatinum and platinum B, if appropriate), at a concentration approximately equal to that which is expected in the sample to be analyzed. A height of 10 cm is noted in the CCM reservoir pre-balanced with the eluent.

The dried plate is sprayed with the freshly prepared developer solution and placed in an oven at 100 ° C for 10 min. We observe the yellow-purple zones.

c) Approximate Rf values 0.65: cisplatin;

0.76: transplatin;

0.90: platinum B.

The titrations by HPLC of the solutions according to the invention tending to determine the cisplatin content can be carried out according to the procedure described in British patent No. 2021946A. The preferred mobile phase consists of a mixture of ethyl acetate / methanol / dimethylformamide / distilled water (25/26/5/5). The standard is preferably constituted by cisplatin dissolved in dimethylformamide at a concentration of 1 mg / ml. The samples to be analyzed are diluted with dimethylformamide to an approximate cisplatin concentration of 1 mg / ml.

Although their presence does not confer any particular advantage, the solutions according to the invention may optionally contain a conventional excipient which is acceptable from the physiological point of view such as mannitol.

From the stability studies carried out at present, it is predicted that the stability of the solutions according to the invention (as being a loss of 10% of power) is greater than two years at room temperature.

According to a preferred aspect of the invention, the solutions are sterile and devoid of pyrogenic substance; they are packaged in sterile containers and devoid of pyrogenic substance. Such solutions can then be diluted with, for example, sterile water for injection, U.S.P. grade, or normal sterile saline, U.S.P. grade, and administered intramuscularly or intravenously. The means for sterilizing such solutions are well known in the art. It is preferred to pass the solutions through a 0.22 µm Millipore filter, sterile and devoid of pyrogenic substance, using aseptic techniques, under sterile nitrogen pressure. Millipore is a trade name of the Millipore Corporation for membrane filters. The sterile filtrate is collected in sterile containers and devoid of pyrogenic substance, then finally introduced in desired quantity, in suitable sterile receptacles, devoid of pyrogenic substance, sealed with sterile stoppers and devoid of pyrogenic substance (preferably coated with Tefion). and hermetically closed with sterile aluminum capsules.

To use them in the treatment of cancer, the concentrated solutions are diluted to the desired concentration (generally

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1 mg cisplatin per milliliter) with, for example, sterile water for injection, USP grade, normal sterile saline solution, USP grade, or sterile glucose solution, used by intravenous or intramuscular injection, or by intravenous infusion , in the manner known until now for the administration of cisplatin preparations.

Doses commonly used, having an acceptable to moderately acceptable mild toxicity, are between 60 and 100 mg / m2 intravenously, administered in a single dose, or distributed over 3 to 5 d, this dose having to be re-administered at intervals of 4 weeks. A dose of 60 mg / m2 is roughly equivalent to a dose of 1.5 mg / kg which, in turn, is roughly equivalent to a dose of 105 mg for a patient weighing 70 kg. Concurrent therapy with other chemotherapeutic agents is frequently prescribed to achieve the best results.

As used in the claims, references to equivalents of chloride ions per equivalent of cisplatin mean molar equivalents. Thus, for example, when using the preferred range between 3 and 7 Eq of chloride ions per equivalent of cisplatin, 3 to 7 mol of NaCl would be used per mole of cisplatin, but 1.5 to 3.5 mol of CaCl2 per mole of cisplatin, etc.

Platinum B is an arbitrary designation used here for the acid reaction product of cisplatin which is half of the known red Magnus complex and to which we have tried to attribute the following structure:

Cl

Pt ^ _ H3N - ^^ Cl _

The invention is illustrated by the following examples, the concentrations being indicated in% by weight.

Example 1:

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

A slurry is made with 500 mg of cisplatin in a solution of 5 ml of normal hydrochloric acid and 45 ml of polyethylene glycol 400. After 2 'd of stirring at room temperature (the container being protected from light to using aluminum foil), a light yellow solution is obtained.

The aliquots of this solution are introduced into 17 ml amber flasks, hermetically closed with Teflon coated stoppers, sealed with aluminum capsules and subjected to storage stability tests at various temperatures. After two weeks 'storage at 56 ° C, thin layer chromatography (TLC) indicates the presence of a trace of transplatin and about 1% platinum B. After two weeks' storage at 56 ° C, TLC indicates the presence of less than 1% of transplatin and approximately 3% of platinum B.

The samples stored for two weeks at 56 ° C. are diluted with, respectively, 4, 9 and 19 volumes of water, and provide transparent solutions containing, respectively, 2.1 and 0.5 mg / ml of cisplatin. A slight cloudiness appears in each of the diluted samples after standing for approximately 18 h at room temperature.

Example 2:

Stable concentrated solution of cisplatin (10 mg / ml) in 90% polyethylene glycol 400/10% 0.5N HCl

5 ml purified water of U.S.P. quality and 5.0 ml of normal HCl are mixed and supplemented with 90.0 ml of polyethylene glycol 400. To 50 ml of the above solution are added 500 mg of cisplatin and the mixture is protected from light with the aid of aluminum foil and stirred at room temperature for 24 hours to produce a clear solution. The TLC of a freshly prepared solution shows only one area of cisplatin with a possible trace of transplatin.

Two 2 ml aliquots of the solution are introduced into 17 ml amber vials, closed with Teflon coated stoppers and sealed with aluminum capsules, then subjected to storage stability tests at various temperatures.

A sample vial is lyophilized in a carbohydrate-acetone ice bath for 1 h, then allowed to warm to room temperature. A clear solution is obtained, and the presence of a precipitate is not observed. After storage for 3 months at 37 and 45 ° C, the TLC indicates the presence of 1 to 2% of platinum B and a possible trace of transplatin.

After 1 month of storage at 56 ° C, the TLC indicates the presence of more than 5% but less than 10% of platinum B and a trace of transplatin.

The samples stored at 37 and 45 ° C for 3 months, and at 56 ° C for 1 month, are diluted with four volumes of purified water of U.S.P quality. to give clear solutions containing 2 mg / ml of cisplatin.

The diluted solutions remain clear after standing for 24 hours at room temperature.

Example 3:

Stable concentrated solution of cisplatin (10 mg / ml) + CaCl2 (20 mg / ml) in 90% polyethylene glycol 400/10% 0.5N HCl

2 g of anhydrous reactive quality calcium chloride are dissolved in a mixture of 5 ml of purified water of U.S.P quality. and 5 ml of normal HCl. 89 ml of polyethylene glycol 400 are added to bring the volume to 100 ml. To 50 ml of this solution, 550 mg of cisplatin is added, and the mixture is protected from light using aluminum foil; the system is stirred at room temperature for 24 h to obtain a clear solution.

The TLC of a freshly prepared solution indicates only the presence of a zone of cisplatin with a possible trace of transplatin. 2 ml aliquots of the solution are placed in 17 ml amber vials, closed with Teflon-coated stoppers, sealed with aluminum capsules and subjected to storage stability tests at various temperatures.

A sample flask and placed in a dry ice-acetone bath for 0.5 h and lyophilized in a transparent gel. This is allowed to warm to room temperature and a clear solution is collected. After storage for 3 months at 37 ° C, the TLC indicates the presence of 1 to 2% of platinum B and a possible trace of transplatin.

After storage for 3 months at 45 ° C, the TLC indicates the presence of approximately 5% of platinum B and a possible trace of transplatin.

After storage for 1 month at 56 ° C., the TLC indicates the presence of 8 to 10% of platinum B and a trace of transplatin.

The samples stored at 37 and 45 ° C for 3 months, and at 56 ° C for 1 month, are diluted with 4 volumes of purified water of U.S.P quality. to give clear solutions containing 2 mg / ml of cisplatin.

The diluted solutions remain clear after standing for 24 hours at room temperature.

Example 4:

Stable concentrated solution of cisplatin (approximately 22 mg / ml) -1- CaCl2 (25 mg / ml) in 90% polyethylene glycol 400/10% HCl 0.5N

3 mg of a 90% solution of polyethylene glycol 400/10% of 0.5N HCl are added with 45 mg of cisplatin, and the mixture is stirred for 1 h at room temperature to give rise to a clear solution.

An additional dose of 30 mg of cisplatin is introduced (making a total of 25 mg / ml) and the mixture is stirred at approximately 45 ° C for 1 h, then at room temperature for 16 h to produce a substantially complete solution. The small amount of

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insoluble matter is removed by filtration. The TLC of the filtrate indicates only a zone of cisplatin with a possible trace of transplatin. The remainder of the filtrate is introduced into a 17 ml amber flask, closed with a Teflon-coated stopper, sealed with an aluminum capsule and kept at 45 ° C for 3 months.

After aging for 3 months at 45 ° C, the TLC indicates that there is 1 to 2% of platinum B and no transplatin in the solution.

A dilution of the aged solution with purified water of U.S.P quality. at a concentration of 2 mg / ml of cisplatin provides clear solutions, which remain so after standing at room temperature for 24 h.

Example 5:

Stable concentrated solution of cisplatin (12 mg / ml) + NaCl (10 mg / ml) in 90% polyethylene glycol 400/10% 0.5N HCl

100 mg of sodium chloride are dissolved in a solution of

5 ml purified water of U.S.P. quality and 5 ml of normal hydrochloric acid. To this solution is added 90 ml of polyethylene glycol 400 and the mixture is stirred for 15 min. 500 ml of cisplatin are added to 50 ml of the solution obtained, and the mixture is stirred in the dark at room temperature for 3 d, to produce a clear solution. The TLC of the freshly prepared solution shows only one spot corresponding to cisplatin. Titration by high performance liquid chromatography (HPLC) of the freshly prepared solution indicates that it contains 12 mg of cisplatin per milliliter.

Aliquots are introduced into 17 ml amber flasks, the latter being sealed as described in Example 3, and subjected to storage stability tests at various temperatures.

After storage at 37 ° C for 3 months, the TLC indicates that there is less than 1% platinum B and no transplatin.

After storage at 56 ° C for 1 month, the TLC indicates that there is 1 to 2% of platinum B and no transplatin.

Diluting aged samples with purified U.S.P. water up to a concentration of 2 mg / ml of cisplatin provides clear solutions which remain so after standing at room temperature for 24 h.

HPLC titrations of samples stored for 3 months at 45 ° C, 6 months at 37 ° C and 8 months at room temperature indicate power losses of 6.6, 6.1 and 2.3% respectively.

Example 6:

Stable concentrated solution of cisplatin (11.4 mg / ml) + NaCl (10 mg / ml) in 90% polyethylene glycol 400/10% water

A solution of 50 mg of NaCl in 5 ml of purified water of U.S.P. quality and 45 ml of polyethylene glycol 400 is added with 500 mg of cisplatin, and the mixture is stirred, in the dark, at room temperature, for 6 h to provide a clear solution.

The TLC of the freshly prepared solution reveals the presence only of the stain corresponding to cisplatin; a titration by HPLC indicates that this solution contains 11.4 mg of cisplatin per milliliter.

Aliquots are introduced into 17 ml amber vials and these are sealed as described in Example 3, then subjected to storage stability tests at various temperatures.

After storage at 37 and 45 ° C for 3 months, the TLC indicates that there is 1% platinum B and no transplatin.

After storage at 56 ° C for 1 month, the TLC indicates that there is 2 to 3% of platinum B and no transplatin.

A dilution of the aged samples with purified water of U.S.P quality at a concentration of 2 mg / ml of cisplatin provides clear solutions which remain so after standing at room temperature for 24 h.

Titrations by HPLC of samples stored for 3 months at 45 ° C,

6 months at 37 ° C and 7 months at room temperature reveal power losses of 6.1, 7.0 and 0.9% respectively.

Example 7:

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

A solution of 2.5 ml of purified water of USP quality, 2.5 ml of normal HCl and 45 ml of polyethylene glycol 600 is supplemented with 500 mg of cisplatin and the mixture is stirred in the dark at room temperature for 5 h, to provide a clear solution.

The TLC of the freshly prepared solution indicates only one spot corresponding to cisplatin.

Samples of the freshly prepared solution are diluted with 1, 2, 3, 4, 5 and 9 volumes of U.S.P purified water, respectively; these dilute solutions show no crystallization after standing for 16 h at room temperature or at 4 ° C.

The aliquots of the freshly prepared solution are introduced into 17 ml amber flasks, which are sealed as described in Example 3, then subjected to the storage stability tests at various temperatures.

After storage at 37 and 45 ° C for 3 months, the TLC indicates that there is 1% platinum B and no transplatin.

After storage at 56 ° C for 1 month, the TLC indicates that there is 3.4% platinum B and no transplatin.

Diluting aged samples with purified U.S.P. water at a concentration of 2 mg / ml of cisplatin provides clear solutions, which remain so after standing at room temperature for 24 h.

Example 8:

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

250 mg of cisplatin is added to a solution of 0.5 g of NaCl in 4 ml of purified water of USP quality, 1 ml of normal hydrochloric acid and 45 ml of polyethylene glycol 400, and the mixture is stirred in the dark. at room temperature, for 4 h, so as to provide a light yellow solution. The TLC of the freshly prepared solution indicates only one spot corresponding to cisplatin. Dilutions of the freshly prepared solution with 1, 2, 3, 4, 5, and 9 volumes of purified water provide clear solutions, which remain so after standing at room temperature for 24 h. Dilutions with 1,2, 3, 4 and 5 volumes show no crystallization when kept at 4 ° C for 24 h. Aliquots of the freshly prepared solution are introduced into 17 ml amber vials, which are sealed as described in Example 3, and subjected to storage stability tests at various temperatures.

After storage at 37 ° C for 3 months, the TLC indicates that there is 1% of platinum B and a possible trace of transplatin.

After storage at 45 ° C for 3 months, the TLC indicates that there is 5% platinum B and a possible trace of transplatin.

After storage at 56 ° C for 1 month, the TLC indicates that there is 2 to 3% of platinum B and no transplatin.

Diluting aged samples with purified U.S.P. water at a concentration of 2 mg / ml of cisplatin provides clear solutions which remain so after standing for 24 h at room temperature.

Example 9:

Stable concentrated solution of cisplatin (2.5 mg / ml), NaCl (9 mg / ml) and mannitol (12.5 mg / ml) in 31% (weight / volume) of acidified aqueous polyethylene glycol 6000

0.9 g of sodium chloride, 1.25 g of mannitol and 31.3 g of polyethylene glycol are dissolved in sufficient purified water of U.S.P. quality. to have 100 ml of a solution, which is acidified to a pH of 2.2 using normal hydrochloric acid (0.7 ml). 255 mg of cisplatin is added and the mixture is stirred in the dark for 3 d at room temperature to obtain a clear solution.

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The TLC of the freshly prepared solution only shows the zone corresponding to cisplatin.

Aliquots of the freshly prepared solution are introduced into 17 ml amber flasks, which are sealed as described in Example 3, then subjected to the storage stability tests at 45 and 56 ° C. After 2 months storage at 45 and 56 ° C, the TLC indicates that there is less than 1% of platinum B and no transplatin.

Diluting aged samples with an equal volume of purified U.S.P. water provides clear solutions, which remain so after standing at room temperature for 24 h.

Example 10:

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

90 ml of polyethylene glycol 400 are dissolved in a solution of 1.0 g of NaCl in 10 ml of purified water of U.S.P quality. 900 ml of cisplatin are added to 60 ml of the solution obtained, and the mixture is stirred in the dark for 5 h at room temperature to obtain a clear solution.

The TLC of the freshly prepared solution indicates only the presence of the zone corresponding to cisplatin; a titration by HPLC indicates that it contains 15.8 mg of cisplatin per milliliter.

Diluting the freshly prepared solution with 4 volumes of purified U.S.P. quality water provides a clear solution, which remains after standing at room temperature for 24 h.

Aliquots of the freshly prepared solution are introduced into 17 ml amber vials, which are sealed as described in Example 3, and then subjected to storage stability tests at various temperatures.

After 2 months of storage at 45 ° C, the TLC indicates that there is 1.5% platinum B and no transplatin.

After 1 month of storage at 56 ° C, the TLC indicates that there is 2% platinum B and no transplatin.

A sample aged at 56 ° C is diluted to a concentration of 2 mg / ml with sterile water for injection, and the sample aged at 45 ° C is diluted to a concentration of 2.5 and 5.0 mg / ml of cisplatin with sterile water for injection. They each provide clear solutions, which remain so after standing at room temperature for 24 hours.

HPLC titrations of samples stored 3 months at 45 ° C, 6 months at 37 ° C and 8 months at room temperature indicate power losses of 7.6, 7.6 and 0% respectively.

Example 11:

Stable concentrated solution of cisplatin (15 mg / ml) + CaCl (25 mg / ml) in 90% aqueous polyethylene glycol 400

A solution of 2.5 g of CaCl2 in 10 ml of purified water of U.S.P. quality 90 ml of polyethylene glycol 400 are added and the resulting solution is stirred for 10 min. To 50 ml of the above solution, 750 mg of cisplatin is added and the mixture is stirred for 5 h in the dark, at room temperature, to obtain a clear solution.

The TLC of the freshly prepared solution indicates only an area corresponding to cisplatin. Dilutions of the freshly prepared solution with 1.2, 5 and 10 volumes of U.S.P. quality purified water respectively. provide a clear solution.

Aliquots of freshly prepared solution are introduced into 17 ml amber flasks, which are sealed as described in Example 3, then subjected to storage stability tests at 45 and 56 ° C.

After storage for 2 months at 45 ° C, the TLC indicates that there is 1.5% platinum B and no transplatin.

After storage for 1 month at 56 ° C, the TLC indicates that there is 2.5 to 5% of platinum B and no transplatin.

A sample aged at 56 ° C. is diluted to a concentration of

2 mg / ml and the sample aged at 45 ° C is diluted to concentrations of 2.5 and 5.0 mg / ml of cisplatin, with sterile water for injection.

They both form clear solutions, which remain after standing at room temperature for 24 h.

Sterile stable concentrated solution of cisplatin in 90% polyethylene glycol 400/10% 0.5N HCl (the label indicates 15 mg / ml of cisplatin activity)

Note: Cisplatin is a possible carcinogen.

You must wear protective clothing, gloves, mask, glasses and cap during the whole procedure.

All work areas and equipment must be thoroughly cleaned to avoid future contamination.

Formula

per milliliter per 10.0 milliliters

Cisplatin1 Sodium chloride Hydrochloric acid 0.5N2 Polyethylene glycol 400 (Sentry quality)

0.015 g 0.150 g 0.015 g 0.150 g 0.10 ml 1.0 ml q.s.p. 1.0 ml q.s.p. 10.0 ml

1 This weight of cisplatin provides a power of 1000 ng / mg.

To determine the amount of cisplatin required, the following formula is used:

1000 x 0.015 g,. ,. .

= grams of cisplatin required power of cisplatin (ng / mg)

2 11 of 0.5N hydrochloric acid is prepared as follows:

1. 957.25 ml of sterile water for injection, of U.S.P quality, are introduced. in an Erlenmeyer flask of 11.

2. With rapid stirring, 42.75 ml of concentrated hydrochloric acid are introduced slowly and carefully. Stirred further for 10 min. Close with a clean butyl rubber stopper.

Manufacturing instructions for preparing a liter of sterile solution

1. 100 ml of 0.5N hydrochloric acid are placed in a clean 11-gauge Erlenmeyer flask containing a suitable stirrer such as a 6 cm magnetic stir bar coated with Teflon.

2. 15.0 g of sodium chloride are added, with gentle stirring. Stirring is continued until complete dissolution.

3. With rapid stirring, 750 ml of polyethylene glycol 400 (Sentry quality) are introduced and stirring is continued for 5 min.

4. Remove the magnetic bar and drain it so that the excess fluid falls back into the bottle.

5. Carefully add 15.0 g of cisplatin activity.

6. Polyethylene glycol 400 (Sentry quality) is added up to mark 11 (a total of 880 ml of polyethylene glycol 400 is required).

7. The Teflon stirrer is returned to the mixture and the system is closed with a clean butyl rubber stopper.

8. The container is wrapped in aluminum foil to protect it from light.

9. Stir quickly for 24 to 48 h at room temperature. We must get a clear solution. If a clear solution is not obtained within 48 h, the mixture can be heated to 37-40 ° C for 2 to 6 h, in the absence of air and light, to facilitate rapid dissolution of the remaining cisplatin. Cool to 23-27 ° C.

10. Using an aseptic technique, the dark yellow solution is passed under a suitable sterile nitrogen pressure, through a suitable 0.22 µl Millipore filter, sterile and devoid of pyrogenic substance. The sterile filtrate is collected in a sterile Erlenmeyer flask devoid of pyrogenic substance. The flask is closed with a sterile stopper, devoid of pyrogenic substance, made of butyl rubber. The solution should be stored in the dark.

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11. The necessary quantity of sterile solution is introduced into sterile amber flasks devoid of pyrogenic substance. These vials are closed with a sterile Teflon stopper and devoid of pyrogenic substance. These vials are hermetically sealed with sterile aluminum capsules.

12. Vials must contain the following warning label:

Product not to be used directly intramuscularly or intravenously *

* The PEG 400 solution can be diluted with 14 parts of sterile water for injection of U.S.P quality. or sterile normal U.S.P. to provide a 1 mg / ml solution of cisplatin. If higher concentrations are required, proportionately smaller amounts of sterile water or saline may be used. The diluted solutions can be used intravenously and are stable at room temperature (22 to 26 ° C) for at least 48 h. Do not put diluted solutions in the refrigerator, as crystals may appear.

13. Keep the vials in the dark.

Example 12:

Stable concentrated solution of cisplatin (2.5 mg / ml), NaCl (9 mg / ml), CaCl2 (15 mg / ml) and mannitol (10 mg / ml) in 31% acidified aqueous polyethylene glycol 400

0.9 g of sodium chloride, 1.5 g of CaCl2 and 1.0 g of mannitol are dissolved in a mixture of 31.25 ml of polyethylene glycol 400 and 40 ml of purified water of U.S.P quality. The solution is acidified to a pH of 2.2 using normal hydrochloric acid (0.4 ml), then 255 mg of cisplatin is added and the volume is brought to 100 ml with purified water of U.S.P quality. The mixture is stirred in the dark

for 5 h, at room temperature, to obtain a clear solution.

The TLC of the freshly prepared solution indicates only one area corresponding to cisplatin.

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Example 13:

The general procedure described in Example 5 is repeated, except that the sodium chloride is replaced by an equivalent amount of magnesium chloride; a stable concentrated solution of cisplatin is thus obtained.

Example 14:

The general procedure described in Example 5 is repeated, except that the sodium chloride is replaced by an equivalent amount of triethylamine hydrochloride; a stable concentrated solution of cisplatin is thus obtained.

Example 15:

The general procedure described in Example 5 is repeated, except that the polyethylene glycol 400 is replaced by an equal volume of polyethylene glycols 200 and 300 respectively. Stable concentrated solutions of cisplatin are obtained.

Example 16:

The general procedure described in Example 9 is repeated, except that the polyethylene glycol 6000 is replaced by an equal weight of polyethylene glycols 1000 and 4000 respectively. Stable concentrated solutions of cisplatin are obtained.

Of course, the present invention is susceptible of numerous-30 variants accessible to those skilled in the art, depending on the applications envisaged and without departing from the spirit of the invention.

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Claims (7)

647481 1. Stable concentrated solution of cisplatin in a solvent medium, characterized in that it comprises from 30 to 95% by weight of polyethylene glycol having an average molecular weight of between 150 and 9000, or of a methoxypolyethylene glycol having a mean molecular weight of between 300 and 6000, or a mixture of these, and from 5 to 70% by weight of water, and moreover also at least one source of non-toxic and pharmaceutically acceptable chloride ions, in an amount which is at least equivalent to the amount of cisplatin present in the solution, this solution having a concentration of cisplatin of between 2.5 and 25 mg / ml. 2. Solution according to claim 1, characterized in that it comprises 80 to 95% by weight of polyethylene glycol having an average molecular weight between 250 and 1600, or of a methoxypolyethylene glycol having an average molecular weight between 300 and 800, or a mixture of these, and 5 to 20% by weight of water, as well as at least one source of non-toxic chloride ions which is acceptable from the pharmaceutical point of view, in an amount which is between 2 and 10 Eq per equivalent of cisplatin in the solution, this solution containing 5 to 20 mg of cisplatin per milliliter. 2 3. Solution according to claim 2, characterized in that the non-toxic and pharmaceutically acceptable source of chloride ions consists of hydrochloric acid, sodium, calcium, magnesium chloride, or hydrochloride. triethylamine, or a mixture thereof. 4. Solution according to one of the preceding claims, characterized in that it comprises 85 to 90% by weight of polyethylene glycol having an average molecular weight of between 250 and 650, and 10 to 15% by weight of water, as well as '' a source of chloride ions chosen from the group formed by hydrochloric acid, sodium chloride or their mixtures, in an amount which is between 3 and 7 Eq per equivalent of cisplatin in the solution, this solution having a concentration in cisplatin between 10 and 15 mg / ml. 5. Solution according to claim 4, characterized in that it is sterile and is in a hermetically closed container, such as a vial. 6. Solution according to claim 5, characterized in that it contains from 10 to 15 mg of NaCl per milliliter of the solvent medium comprising approximately 90% by weight of a polyethylene glycol having an average molecular weight of between 350 and 450, and approximately 10% by weight of water. 7. Solution according to claim 5, characterized in that it contains from 10 to 15 mg of NaCl per milliliter of the solvent medium comprising approximately 90% by weight of a polyethylene glycol having an average molecular weight of between 350 and 450, and approximately 10% by weight of dilute hydrochloric acid, the concentration of which can be up to 0.5N.