阿莫西林原料药中未知杂质的研究

Research on unknown impurities in amoxicillin API

目的对阿莫西林原料药中的一个含量略大于0.05%的未知单杂进行分离纯化并鉴定结构。方法采用制备HPLC对阿莫西林原料药中的一个未知杂质进行富集、分离和纯化,得到高纯度杂质样品并通过高分辨质谱(HRMS)、核磁共振(NMR)技术及HPLC进行杂质结构的确证。结果阿莫西林原料药中目标杂质的结构为(2S,3R,5R,6R)-3-甲基-3-乙基-6-[(R)-(-)-2-氨基-2-(4-羟基苯基)乙酰氨基]-7-氧代-4-硫杂-1-氮杂双环[3.2.0]庚烷-2-甲酸,即阿莫西林C3位上的一个甲基被乙基替代后形成了五元环3-甲基-3-乙基二取代阿莫西林的衍生物。结论该杂质系首次从阿莫西林原料药中鉴定出来,其与阿莫西林结构密切相关,归为无新的高毒性结构杂质即一般杂质,建议可在原料质量标准中对其适当放宽限度。

Objective To isolate,purify and identify the structure of an unknown impurity with a content slightly greater than 0.05%in amoxicillin raw materials.Methods The unknown impurity in amoxicillin raw material were enriched,separated,and purified using preparative HPLC to obtain high-purity impurity samples.The impurity structure was confirmed by high-resolution mass spectrometry(HRMS),nuclear magnetic resonance(NMR)technology and HPLC.Results The structure of an unknown impurity in amoxicillin raw material was(2S,3R,5R,6R)-3-methyl-3-ethyl-6-[(R)-(-)-2-amino-2-(4-hydroxyphenyl)acetylamino]-7-oxo-4-thia-1-azabicyclic[3.2.0]heptane-2-carboxylic acid,where a methyl group on the C3 position of amoxicillin was replaced by ethyl to form a derivative of pentacyclic 3-methyl-3-ethyl disubstituted amoxicillin.Conclusion This impurity was identified for the first time in the amoxicillin raw material and was closely related to the structure of amoxicillin.It could be classified as a general impurity with no new high-toxicity structure.It was recommended to appropriately increase the limits of the target impurity in the quality control of raw materials.