Novel crystalline 7-(2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido)-3-vinyl-3-cephem-4-carboxylic acid (syn isomer)

Abstract: Crystalline 7-[2-(2-aminothiazol-4-yl)-2-hydroxyimino­ acetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) which is obtainable by acidifying a solution containing 7-[2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido-3-vinyl-­ 3-cephem-4-carboxylic acid (syn isomer) at room temperature or under warming. Such crystalline compound shows a characteristic X-ray diffraction pattern. The invention comprises also processes for preparing such crystalline compound and pharmaceutical compositions containing it as active ingredient.

Description: The present invention relates to novel crystalline 7-[2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) [hereinafter referred to as "the compound (I)" in the present specification] as shown by the following formula (I): processes for its preparation and pharmaceutical compositions containing it. The compound (I), which is a very useful antimicrobial agent, is a known compound and was described, for example, in U.S. Patent 4,559,334 as the object compounds of Examples 14 and 16. Our further experimental investigation revealed that the compound (I) each prepared according to the procedure of said Examples 14 and 16 in said U.S. Patent 4,559,334 was a crystalline-like amorphous product, not a crystalline product. However, the amorphous product has the disadvantages that it is bulky, not so pure, unstable and insufficient in filtration rate. Therefore, it is not suitable for a pharmaceutical product or is not easy to handle in pharmaceutical preparations, in producing it in a large scale or in storage. After an intensive study, the inventors of the present invention succeeded in obtaining the compound (I) as a special crystalline form, i.e. Crystal A, and completed the present invention, which is explained in detail as follows. According to a first aspect the present invention relates to the compound (I) per se having the above formula. Physicochemical Properties of Crystal A of The Compound (I) The physico-chemical properties of Crystal A of the compound (I) provided by the present invention are explained in the following. 1) Crystal Form prisms 2) Powder X-Ray Diffraction Pattern Crystal A of the compound (I) shows its distinguishing peaks at the diffraction angles [20 (°)] as shown in the following table, the measurement condition being as follows: Target: Cu Filter: Ni Voltage: 30 kV Current: 10 mA Detector: Scintillation Counter According to a second aspect the present invention relates to processes for preparing the compound (I) as defined below. The Process For Preparing Crystal A of The compound (I) In the following, the process for the preparation of Crystal A of the compound (I) of the present invention is explained in detail. Crystal A of the compound (I) can be obtained by dissolving the compound (I) in an alcohol (preferably methanol), continuing to stir this solution slowly under warming (preferably below 40°C), preferably after the addition of water warmed at almost the same temperature as that of said solution, then cooling this solution to room temperature and allowing it to stand. During the crystallization of Crystal A, it is preferable to keep the condition of slightly beyond the saturation. Crystal A of the compound (I) obtained according to aforesaid process can be collected by filtration and dried by means of the conventional methods. The water content of Crystal A of the compound (I) obtained above is about 0.8% (measured by Karl Fisher method). According to a third aspect the present invention relates to a pharmaceutical composition containing the crystalline compound (I) as defined above as active ingredient in association with a pharmaceutically acceptable, substantially non-toxic carrier or excipient. According to further aspects the present invention relates to the use of the crystalline compound (I) as defined above for manufacture of a medicament for treating or preventing infectious diseases; to the crystalline compound (I) as defined above for use as a medicament and to the crystalline compound (I) as defined above for use in treating or preventing infectious diseases. The Advantages of The Crystal A of The Compound (I) The Crystal A of the compound (I) is not bulky, is very pure and is very stable against heat and light. Therefore, the Crystal A of the compound (I) is suitable for a pharmaceutical product and is easy to handle in pharmaceutical preparations and in storage. Further, the Crystal A of the compound (I) has sufficient filtration rate and the operation efficiency in case of producing it is very high. Therefore, the Crystal A of the compound (I) is very suitable to produce even in a large scale such as a laboratory scale. Moreover, due to its ease to be filtered, impurities are difficult to mix in the purification step. Therefore, the compound (I) with high quality can be produced. As stated above, the Crystal A of the compound (I) possesses very good advantages and is much superior to the amorphous product of the compound (I) known from U.S. patent 4,559,334. In order to show said advantages of the Crystal A of the compound (I), the comparative test results on stability between the Crystal A of the compound (I) and the compound (I) given by aforesaid U.S. Patent 4,559,334 are shown in the following. Test Sample Sampe 1 - the compound (I) obtained in Example 14 of U.S. patent 4,559,334 Sample 2 - the compound (I) obtained in Example 16 of U.S. patent 4,559,334 Sample A - Crystal A of the compound (I) of the present invention Test Method The stability of each test sample was examined under the condition of 50°C in a closed container. Color of the solution of each sample was determined by measuring transmittance at 510 nm with spectrophotometer (T %) (1 % solution in 1 % NaHCO₃ aqueous solution was used). The potency of each sample was determined by liquid chromatography and the residual percentage to the initial value was calculated. Test Results Test Sample Test Item Initial After 1 day After 7 days Sample 1 appearance pale brownish yellow powder ditto brownish yellow powder color of the solution(T%) 47.0 39.2 25.5 potency (%) 100 97.2 85.1 Sample 2 appearance yellow powder ditto brownish yellow powder color of the solution(T%) 63.8 54.5 37.3 potency (%) 100 89.3 52.4 Sample A appearance yellowish white crystal ditto ditto color of the solution(T%) 98.9 98.9 98.7 Potency (%) 100 99.8 99.4 As shown in the test results, there was slight change in the appearance of Samples 1 and 2, while there was no change in the appearance of Sample A. Further, there was significant lowering of the transmittance (T %) in case of Samples 1 and 2, while there was almost no lowering in case of Sample A. These results indicated that Samples 1 and 2 were much easier to discolor than Sample A. Further, as shown in the test results, the potency of Samples 1 and 2 apparently decreased, while the potency of Sample A was almost unchanged. As stated above, only after 7 days there appeared much difference regarding the stability between the Crystal A of the compound (I) and the compound (I) given by U.S. Patent No. 4,559,334. Namely, it turned out that the Crystal A of the compound (I) was much superior to the compound (I) given by said U.S. Patent. The Preparation Of Crystal A Of The Compound (I) Example 1 To a solution of 7-[2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer)(an amorphous product)(0.5 g) in methanol (10 ml) was added dropwise warm water (35°C; 1.5 ml) at 35°C and the resultant solution was stirred slowly for 3 minutes, then allowed to stand at room temperature. The resultant crystals were collected by filtration, washed with water and then dried to give 7-[2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) as crystals (Crystal A) (0.4 g). IR (Nujol®) : 1760, 1670, 1620 cm⁻¹ In the following, powder X-ray diffraction pattern of this Crystal A was shown. The measurement condition was as follows. Target : Cu Filter : Ni Voltage : 30 kv Current: 10 mA Detector : Scintillation Counter 2ϑ (° ) relative intensity 11.7 18 12.5 15 14.7 76 16.6 16 17.8 56 18.9 22 19.1 16 21.5 100 22.0 70 23.4 38 24.4 80 25.3 22 26.9 10 27.6 22 28.0 40 29.6 18

Claims: Claims for the following Contracting States : AT, BE, CH, LI, DE, FR, GB, IT, LU, NL, SE Crystalline 7-[2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) which shows the peaks at the diffraction angles shown in the following table in its powder X-ray diffraction pattern, the measurement condition being as follows: Target: Cu Filter: Ni Voltage: 30 kV Current: 10 mA Detector: Scintillation Counter Crystalline 7-[2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) which is obtainable by dissolving 7-[2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) in an alcohol, continuing to stir the solution slowly under warming, then cooling the solution to room temperature and allowing the solution to stand. A process for preparing crystalline 7-[2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) which comprises dissolving 7-[2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) in an alcohol, continuing to stir the solution slowly under warming, then cooling the solution to room temperature and allowing the solution to stand. A pharmaceutical composition containing the crystalline compound of any of claims 1 to 3 as active ingredient in association with a pharmaceutically acceptable, substantially non-toxic carrier or excipient. A use of the compound of any of claims 1 to 3 for manufacture of medicament for treating or preventing infectious diseases. A crystalline compound of any of claims 1 to 3 for use as a medicament. A crystalline compound of any of claims 1 to 3 for use in treating or preventing infectious diseases. Claims for the following Contracting State : ES A process for preparing crystalline 7-[2-(2-aminothiazol-4-yl)-2-hydroxyimonoacetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) which shows the peaks at the diffraction angles shown in the following table in its powder X-ray diffraction pattern, the measurement condition being as follows: Target: Cu Filter: Ni Voltage: 30 kV Current: 10 mA Detector: Scintillation Counter which comprises dissolving 7-[2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) in an alcohol, continuing to stir the solution slowly under warming, then cooling the solution to room temperature and allowing the solution to stand. A process for preparing crystalline 7-[2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) which comprises dissolving 7-[2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) in an alcohol, continuing to stir the solution slowly under warming, then cooling the solution to room temperature and allowing the solution to stand. A process for preparing a pharmaceutical composition comprising mixing the crystalline compound of any of claims 1 to 2 as active ingredient with a pharmaceutically acceptable, substantially non-toxic carrier or excipient. A process for preparing a pharmaceutical composition containing crystalline 7-[2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) which comprises dissolving 7-[2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) in an alcohol, continuing to stir the solution slowly under warming, then cooling the solution to room temperature and allowing the solution to stand, and mixing it as active ingredient with a pharmaceutically acceptable, substantially non-toxic carrier or excipient. A process of using the compound of any of claims 1 to 2 for manufacture of medicament for treating or preventing infectious diseases.

Inventors: INABA YASUNOBU, NAKAMURA HITOSHI, SHIRAI FUMIYUKI, TAKAYA TAKAO, INABA, YASUNOBU, NAKAMURA, HITOSHI, SHIRAI, FUMIYUKI, TAKAYA, TAKAO
Applicants: FUJISAWA PHARMACEUTICAL CO, FUJISAWA PHARMACEUTICAL CO., LTD.
Application year: 1988
Main classification: A61K31
IPC codes: A61K31, C07D501