盐酸头孢吡肟中N-甲基吡咯烷测定方法的比较

目的:比较HPLC和GC法测定盐酸头孢吡肟中杂质N-甲基吡咯烷(NMP)的优劣.方法:分别采用HPLC法和GC法对盐酸头孢吡肟中的NMP进行测定,并对HPLC法中供试品溶液的降解情况进行了反应动力学分析.结果:3批样品中NMP的含量在HPLC法测定结果均为0.05%,GC法分别为0.006%,0.005%和0.005%,两者相差约10倍.HPLC法的供试品溶液中盐酸头孢吡肟的降解反应呈近似零级反应,即NMP的生成速率恒定,每小时增加约为0.084%.HPLC法测定的是盐酸头孢吡肟水溶液中的NMP,其含量实际在不断增加,而GC法测定的是盐酸头孢吡肟固体中氯仿提取的NMP,其含量基本不变.结论:GC法测定盐酸头孢吡肟中NMP较为合理.

Comparative study of two methods for determination of N-methylpyrrolidine in cefepime hydrochloride

Objecive:To compare the HPLC method and the GC method for determination of N-methylpyrrolidine(NMP) in csfepime hydrochloride. Methods:These two methods were applied in the test of NMP, and the degrada ion of cefepime hydrochloride in the test solution of HPLC method was investigated using reaction kir etics. Results:The content of NMP of 3 batches of samples with HPLC method were all 0. 05 % and were about 10 times that of the GC method, which were 0. 006%, 0.005% and 0.005% ,respectively. Degradation reaction of cefepime hydrochloride in the test solution of HPLC method proved to be a zero-order reaction approximately,i. e. NMP in the solution had an almost constant creation speed of 0.084% per hour. What the HPLC method detected was NMP in the solution of cefepime whose cor tent increased gradually,while what the GC method detected was that in solid state of cefepime which kept almost constant.Conclusion:The GC method is simple and accurate for NMP control in cefepime hydrochloride.