卡德沙星主要相关杂质的分析和鉴定卡德沙星主要相关杂质的分析和鉴定

目的卡德沙星原料药中相关杂质的分离及结构鉴定。方法用液相色谱-质谱联用技术分离并鉴定卡德沙星原料药中的主要相关杂质,并合成了化合物:1-环丙基-8-二氟甲氧基-6-氟-1,4-二氢-7-(1-哌嗪基)-4-氧代-3-喹啉羧酸(简称DMCA)。比较合成的化合物与原料药中相关杂质的液相色谱、紫外吸收光谱及质谱。结果相关杂质的分子量比卡德沙星少14,即一个亚甲基,推测该杂质可能为卡德沙星中3-甲基哌嗪的去甲基化合物,合成的DMCA的液相色谱、紫外吸收光谱及质谱分析结果与原料药中相关杂质一致。结论确证了该相关杂质的结构为1-环丙基-8-二氟甲氧基-6-氟-1,4-二氢-7-(1-哌嗪基)-4-氧代-3-喹啉羧酸。

Analysis of impurity in caderofloxacin

AIM: To analyse the main impurity of caderofloxacin. METHODS: The impurity of caderofloxacin was analysed and determinated by RP-HPLC/ESI/MS with a Zorbax SB-C18 (150 mm x 4.6 mm ID, 5 microns) column. The mobile phase was acetonitrile-0.5% acetic acid solution (17:83). A compound was synthesized: 1-cyclopropyl-8-(difluoromethoxy)-6-fluoro-1, 4-dihydro-7-(1-piperazinyl)-4-oxo-3-quinoline carboxylic acid (DMCA). Its HPLC chromatogram, UV and MS spectrum were compared with those of the impurity in caderofloxacin. RESULTS: The molecular weight of the impurity was 14 less than that of caderofloxacin. It means the impurity was a CH2-group less than caderoflixacin. The tR, UV and MS of DMCA were the same as those of the impurity in caderofloxacin. CONCLUSION: Based on the tR (HPLC), UV and MS, the impurity of caderofloxacin is confirmed as DMCA.