FREEZE-DRIED PHARMACEUTICAL COMPOSITIONS OF PHENYLQUINOLINE CARBOXYLIC ACIDS

Abstract: Freeze-dried pharmaceutical compositions of antitumor phenylquinoline carboxylic acids, such as 6-fluoro-2-(2′-fluoro-1′-biphenyl-4-yl)-3-methyl-4-quinolinecar oxylic acid, sodium salt, reconstitutable to stable, aqueous, injectable compositions are provided. These compositions use a stabilization system consisting essentially of a bile salt, such as sodium cholate or sodium desoxycholate, and a base or buffer that will provide a pH of about 8.5-11 upon aqueous reconstitution. Glycine is the preferred buffer.

Description: Field of the Invention : This invention relates to a freeze-dried pharmaceutical compositions and stable, aqueous, injectable compositions reconstitutable therefrom. More particularly this invention relates to such compositions which use bile salts in the stabilization system for antitumor phenylquinolinecarboxylic acids. Background of the Invention : Phenylquinolinecarboxylic acids are disclosed as antitumor agents in coassigned U.S. Application Serial No. 727,808 filed April 26, 1985. These agents are also described in EPO published Application No. 0133,244, published February 20, 1985. However, in order to avoid contamination or risk from spillage or aerosol inhalation during ampul opening, a freeze-dried powder is a preferred dosage form for these agents. To prepare a freeze-dried product, it is required to make up a drug solution which can be filtered, filled into suitable containers, and lyophilized to form an elegant cake. Also, after being reconstituted, the drug solution should be free of particulates and be ready for intravenous administration. The phenylquinolinecarboxylic acids, when in acid form, are insoluble in water. The solutions prepared with the salts of the acids are unstable and have a tendency to form precipitates after a short period of time. Precipitation occurs even at a concentration as low as 100 µg/ml while a solution up to 125 mg/ml is needed for product preparation. It is apparent that solubilizers which can enchance the solubility of these phenylquinolinecarboxylic acids are needed. Solubilization techniques are known in the art, but such techniques depend on the drugs being formulated. For example, using a co-solvent or a complexation agent for drug solubility enchancement was found useful in some pharmaceutical applications. Such examples can be found in "Techniques of Solubilization of Drugs", edited by S. H. Yalkowsky, chapter 3, page 91. However, these techniques are not practical for preparing freeze-dried compositions that are reconstituted to intravenous products. For example, co-solvents such as ethyl alcohol, benzyl alcohol and propylene glycol can solubilize a drug to a desirable concentration, but due to the liquid nature of these co-solvents, preparation of freeze-dried powders with these co-solvents is difficult. Attempts to use a complexation agent such as niacinamide up to a complexation agent such as niacinamide up to a physiologically acceptable concentration with phenylquinonecarboxylic acids fails to prevent the acids from precipitation. Another procedure which has been used to improve the solution stability with some drugs is to use micellar solubilization techniques with suitable solubilizers. However, to identify a useful solubilizer is a challenging task for parenteral formulators because the micelle from each solubilizer behaves differently. For example, the micelles formed from some commonly used solubilizers such as Tween® 20, Tween® 80, and Emulphor® 719P and Pluronic® F-68 do not have enough solubilization capacity to prevent the quinolinecarboxylic acids from precipitating. Also, incorporating these solubilizers in the parenteral formulation can either result in a change in drug activity due to the inclusion of the drug into the hydrophobic micellar core or cause toxicity to increase due to the surface activity of these solubilizers. U.S. Patent 4,478,829, issued October 23, 1984, describes the use of bile salts as surface active agents, in the same category as the Polysorbates, Triton® X100 and Pluronic® F-68 surfactants, in the preparation of lyophilized fibronectin which is readily reconstitutable with sterile water. Similarly, the bile salt sodium desoxycholate is described in published European Patent Application No. 141922-A1 in combination with freeze-drying to reduce turbidity in reconstituted clinical control sera. U.S. Patent 4,036,954, issued July 19, 1977, describes the use of a salt of desoxycholic acid as an addition in the lyophilization of a prostaglandin E group compound. It is known that the freeze-drying technique can be used to convert a drug formulation from an aqueous mixture into a solid form. It is surprising to find that in this invention the antitumor phenylquinolinecarboxylic acid compounds can be successfully formulated into stable aqueous injectable compositions by employing a specially selected type of solubilizer in conjunction with the freeze-drying technique. DE-433 646 discloses the solubilization of a phenylquinoline carboxylic acid using an alkali choleate. According to this document, the drug: excipient ratio is 1 : 1.2 which is greatly exceeding the estimated daily intake of sodium choleate of 75 mg/day/60 kg body weight. It is further described in this document that a solution of sodium choleat is heated with an excess of phenylquinoline carboxylic acid and thereafter filtrated. AT-A-356 278 describes a solubilizing composition containing a bile acid derivative and lipoid substances such as phosphatides. It is known that such compositions containing lipoid substances are emulsions, which are turbid or cloudy in appearence. EP-A-0 179 583 describes the use of various surfactants to solubilize poorly water soluble drugs. Summary Of The Invention: According to the present invention there is provided a powder pharmaceutical composition suitable for reconstitution into a parenteral solution consisting essentially of a freeze-dried mixture of (a) sodium or potassium salt of a phenylquinolinecarboxylic acid and (b) a stabilization system characterized in that said stabilization system consists of (1) a bile salt and (2) a pharmaceutically acceptable base or buffer that will give a pH in the range of 8.5 to 11 upon aqueous reconstitution, the weight ratio of (a) to (b)(1) being in the range of 1:0.1 to 1:0.8. There is also provided a stable, injectable pharmaceutical composition comprising: an aqueous solution of 1 part by weight of a salt of a drug which in free acid form has an aqueous solubility in the µg/ml range at room temperature, at least 0.1 part by weight of a bile salt per part of drug, and sufficient pharmaceutically acceptable base or buffer to provide a pH in the range of 8.5-11. Detailed Description Of The Invention: In this invention, it was discovered that bile salts, which are major breakdown products of cholesterol in humans, are useful solubilizers to prevent salts of phenylquinolinecarboxylic acids from precipitating during the preparation of bulk solution and upon reconstituting from the freeze-dried form. Drug solutions prepared with these solubilizers are stable and can be easily freeze-dried to form elegant cakes without change in potency. After being reconstituted with water for injection, the solution remained clear and suitable for intravenous administration. Further studies also indicated that there is little change in drug activity and toxicity when the drug and bile salt solubilizers were dissolved together in the solution. The freeze-dried powder formulation described in this invention consist essentially of an active antitumor ingredient, a salt of a phenylquinolinecarboxylic acid, preferably 6-fluoro-2-(2'-fluoro-1'-biphenyl-4-yl)-3-methyl-4-quinolinecarboxylic acid, sodium salt, or 2-(1,1'-biphenyl-4-yl)-5-chloro-3-methyl-4-quinolinecarboxylic acid, sodium salt, and a stabilization system. The stabilization system consists essentially of a bile salt solubilizer and a pharmaceutically acceptable buffer or base that will adjust pH to 8.5-11 in aqueous solution. While any salt of the phenylquinolinecarboxylic acids described in EP-133,244-A1 can be used, the preferred acid salts are those described above. The bile salts useful in the stabilization system are preferably sodium cholate or sodium desoxycholate. Other alkali metal salts (lithium, potassium) or organic salts can also be used. Salts of other bile acids are also useful. These include dehydrocholic acid, lithocholic acid, hydrodeoxycholic acid, chenodeoxycholic acid, glycodeoxycholic acid, taurodeoxycholic acid, glycocholic acid, and taurocholic acid. Any pharmaceutically acceptable base or buffer can be used in the compositions that will give an initial aqueous pH or a pH upon aqueous reconstitution in the range of 8.5-11, preferably a pH of 9. Useful buffers and bases include sodium glutamate, sodium phosphate, glycine, sodium hydroxide, triethanolamine, and sodium carbonate. Preferred materials are glycine or sodium hydroxide. Glycine is particularly preferred. The amounts of materials in the compositions are based on the drug, e.g., the salt of a phenylquinolinecarboxylic acid. For every 1 part by weight of the drug, at least 0.1 part by weight of bile salt is required. Typically, the preferred weight ratio of drug to bile salt is in the range of 1:0.1 to 1:0.8. The invention can be further understood by the following examples. Example 1 Freeze-dried Formulation Containing 6-Fluoro-2-(2'-fluoro-1'-biphenyl-4-yl)-3-methyl-4-quinolinecarboxylic Acid, Sodium Salt Each 10 ml vial contained the title compound (100 mg), sodium cholate (40 mg), and glycine (40 mg). For Manufacture of 250 Vials: The title compound (25 g) was suspended in a solution of sodium cholate (10 g) and glycine (10 g) in water for injection (950 ml). The pH of the resulting suspension was adjusted to 9.0-9.5 with 1 N NaOH and the mixture was stirred until it was clear. The solution was then adjusted to 1000 ml by adding water for injection with stirring and then filtered through a 0.22 µm filter. Each 10 ml vial was aseptically filled with 4 ml of the filtered solution. The vials were placed in a lyophilizer and frozen to -40° to -45°C for two hours. The condenser was turned on and the temperature allowed to reach -60°C. The vials were then vacuumed at 6.67-13.33 Pa (50-100 milliTorr) at 20°C for 24 hours. Finally, the vials were dried at 45°C for two more hours to give an elegant white cake which was reconstituted with water (4 ml) for injection to a stable solution for intravenous use. The 24-hour stability data for the reconstituted solution of the title compound is shown in Table I. Drug concentrations were determined by high pressure liquid chromatography (HPLC). The mean value is based on four separate aliquots taken from a composite sample. Example 2 Freeze-dried Formulation Containing 2-(1,1′-Biphenyl-4-yl)-5-chloro-3-methyl-4-quinolinecarboxylic Acid, Sodium Salt Each 10 ml vial contained the title compound (100 mg), sodium desoxycholate (50 mg), and glycine (50 mg). This formulation was prepared in a manner similar to that described in Example 1. A powder of similar properties was obtained. Example 3 Freeze-dried Formulation Containing 6-Fluoro-2-(2′-fluoro-1,1′-biphenyl-4-yl)-3-methyl-4-quinolinecarboxylic Acid, Sodium Salt Each 10 ml vial contained the little compound (100 mg), sodium cholate (80 mg) and sodium hydroxide (enough to make pH 9.0). This formulation was prepared in a manner similar to that described in Example 1. A powder of similar properties was obtained. Example 4 Freeze-dried Formulation Containing 6-Fluoro-2-(2'-fluoro-1'-biphenyl-4-yl)-3-methyl-4-quinolinecarboxylic Acid, Sodium Salt Each 20 ml vial contained the title compound (500 mg), sodium cholate (80 mg), and glycine (80 mg). For manufacture of 250 vials: The title compound (125 g) was suspended in a solution of sodium cholate (20 g) and glycine (20 g) in water for injection (1195 ml). The pH of the resulting suspension was adjusted to 9.0-9.5 with 1 N NaOH and the mixture was stirred until it was clear. The solution was then adjusted to 2000 ml by adding water for injection with stirring and then filtered through a 0.22 µm filter. Each 20 ml vial was aseptically filled with 8 ml of the filtered solution. The vials were placed in a lyophilizer and frozen to -40° to -45°C for six hours. The condenser was turned on and the temperature allowed to reach -60°C. The vials were then vacuumed at 6.67-13.33 Pa (50-100 milliTorr) at 20°C for 24 hours. Finally, the vials were dried at 45°C for four more hours to give an elegant white cake which was reconstituted with water (8 ml) for injection to a stable solution for intravenous use. Example 5 Stability Studies on Freeze-dried 6-Fluoro-2-(2'-fluoro-1'-biphenyl-4-yl)-3-methyl-4-quinolinecarboxylic Acid, Sodium Salt The title compound was formulated as described in Example 1. The freeze-dried powder was sealed in 10 ml vials and stored at various conditions for stability observation. As shown in Table II, the formulated samples are chemically stable. However, by visual inspection, a light brown color developed upon exposure to excessive light. Example 6 In Vivo Antitumor Activity of Formulated 6-Fluoro-2-(2′-fluoro-1,1′biphenyl-4-yl)-3-methyl-4-quinoline-carboxylic Acid, Sodium Salt A solution (1 ml) containing the title compound (25 mg), sodium cholate (10 mg), and glycine (10 mg) was prepared with the same composition as that of the reconstituted solution described in Example 1. Then distilled water (4 ml) was added to the above to make 50 mg/kg solution. Serial two-fold dilutions were made in distilled water from the 50mg/kg solution for the remaining three concentrations. An unformulated control solution was prepared by dissolving the title compound in distilled water and was used while it remained clear. The antitumor activity of the formulated and unformulated material against L1210 leukemia in mice is shown in Table III. The test was carried out as follows. On day O, CDFI mice were injected with 1×10⁵ L1210 murine leukemia cells intraperitoneally. On day 1 formulated and unformulated title compound were injected intraperitoneally and the injections continued, once daily through day 9. Mice were observed until death. These testing results show that sodium cholate and glycine have no effect on the antitumor activity of the title compound. Example 7 Safety comparison of Formulated 6-Fluoro-2-(2′-fluoro-1′-biphenyl-4-yl)-3-methyl-4-quinolinecarboxylic Acid, Sodium Salt in Distilled Water and in 1% Sodium Cholate/1% Glycine. A comparative test was performed on the title compound to evaluate possible lethality differences between compositions described herein and compositions prepared by dissolving in water. The title compound was formulated into a freeze-dried composition as in Example 1 and reconstituted with water prior to injection. The two solutions of the title compound were parenterally administered to female B₆C₃F₁ mice weighing between 17-22 grams at single dosages of 0, 120, 144, 173, and 200 mg/kg. Following compound administration, mortality was evaluated twice daily for 14 days. LD₅₀ values, their corresponding 95% confidence intervals and the slope of the response curves are as follows: Additionally, ten female B₆C₃F₁ mice were administered a single dose of the 1% sodium cholate/glycine (pH = 9.0) vehicle intravenously at 10 mL/Kg. No mortalities were observed as a result of this control vehicle administration.

Claims: Claims for the following Contracting States : BE, CH, DE, FR, GB, IT, LI, LU, NL, SE A powder pharmaceutical composition suitable for reconstitution into a parenteral solution consisting of a freeze-dried mixture of (a) sodium or potassium salt of a phenylquinolinecarboxylic acid and (b) a stabilization system characterized in that said stabilization system consists of (1) a bile salt and (2) a pharmaceutically acceptable base or buffer that will give a pH in the range of 8.5 to 11 upon aqueous reconstitution, the weight ratio of (a) to (b)(1) being in the range of 1:0.1 to 1:0.8. The powder composition of Claim 1 wherein the bile salt (b)(1) is a salt of cholic acid or desoxycholic acid. The powder composition of Claim 1 or 2 wherein the base or buffer (b)(2) is glycine or sodium hydroxide sufficient to give a pH upon aqueous reconstitution of 9. The powder composition of Claims 1 to 3 wherein the phenylquinolinecarboxylic acid salt is 6-fluoro-2-(2'-fluoro-1'-biphenyl-4-yl)-3-methyl-4-quinolinecarboxylic acid, sodium salt or 2-(1,1'-biphenyl-4-yl)-5-chloro-3-methyl-4-quinolinecarboxylic acid, sodium salt. A powder pharmaceutical composition suitable for reconstitution into a parenteral solution consisting essentially of a freeze-dried mixture of (a) 1 part by weight of 6-fluoro-2-(2'-fluoro-1'-biphenyl-4-yl)-3-methyl-4-quinolinecarboxylic acid, sodium salt, and (b) a stabilization system consisting essentially of (1) 0.1 to 0.8 parts by weight of sodium cholate, and (2) sufficient glycine to give a pH of 9 upon aqueous reconstitution. Use of the powder pharmaceutical composition as defined in anyone of claims 1 to 5 for the manufacture of stable aqueous injectionable compositions for the treatment against tumors. Claims for the following Contracting States : AT, ES, GR Process for the manufacture of a powder pharmaceutical composition suitable for reconstitution into a parenteral solution consisting of a freeze-dried mixture of (a) sodium or potassium salt of a phenylquinolinecarboxylic acid and (b) a stabilization system wherein said stabilization system consists of (1) a bile salt and (2) a pharmaceutically acceptable base or buffer that will give a pH in the range of 8.5 to 11 upon aqueous reconstitution, the weight ratio of (a) to (b)(1) being in the range of 1:0.1 to 1:0.8, said process comprising suspending the sodium or potassium salt of the phenylquinoline carboxylic acid in a solution of the bile salt and the pharmaceutically acceptable base or buffer in water, optionally adjusting the pH by adding 1 N NaOH, stirring said solution and subsequently freeze-drying it. The process of Claim 1 wherein the bile salt (b)(1) is a salt of cholic acid or desoxycholic acid. The process of Claim 1 or 2 wherein the base or buffer (b)(2) is glycine or sodium hydroxide sufficient to give a pH upon aqueous reconstitution of 9. The process of Claims 1 to 3 wherein the phenylquinolinecarboxylic acid salt is 6-fluoro-2-(2'-fluoro-1'-biphenyl-4-yl)-3-methyl-4-quinolinecarboxylic acid, sodium salt or 2-(1,1'-biphenyl-4-yl)-5-chloro-3-methyl-4-quinolinecarboxylic acid, sodium salt. A process according to claim 1 for the manufacture of a powder pharmaceutical composition suitable for reconstitution into a parenteral solution consisting essentially of a freeze-dried mixture of (a) 1 part by weight of 6-fluoro-2-(2'-fluoro-1'-biphenyl-4-yl)-3-methyl-4-quinolinecarboxylic acid, sodium salt, and (b) a stabilization system consisting essentially of (1) 0.1 to 0.8 parts by weight of sodium cholate, and (2) sufficient glycine to give a pH of 9 upon aqueous reconstitution. Use of the powder pharmaceutical composition as defined in anyone of claims 1 to 5 for the manufacture of stable aqueous injectionable compositions for the treatment against tumors.

Inventors: WU, CHIEN-CHIN
Applicants: THE DU PONT MERCK PHARMACEUTICAL COMPANY
Application year: 1987
Main classification: A61K9
IPC codes: A61K9, A61K47, A61K31