Identification and characterization of new impurity in Cefotaxime Sodium drug substance

摘要

Cefotaxime Sodium is a third generation cephalosporin drug substance. During the analysis of Cefotaxime Sodium in our lab, one unknown impurity was detected in gradient reverse phase High Performance Liquid Chromatography (HPLC) analysis at level ranging from 0.05 to 0.2% along with known impurities. This new impurity was detected by HPLC and have been identified by LCMS and was not reported in literature. The impurity was synthesized, isolated & characterized. Based on the spectral data, the impurity was named as, (6R,7R)-7-[(Z)-2-(2- amino-4-thiazolyl)-2-(methoxyimino)acetamido]-3-[[(2-benzothiazolyl)thio]methyl]-3-cephem- 4-carboxylic acid. The structure was established unambiguously by independent synthesis and co-injection in HPLC to confirm the retention time. Structural elucidation of this impurity by using spectral data (1H NMR, 13C NMR, MS and IR), synthesis, isolation, formation, validation and stability elucidation of this impurity has been discussed in detailed in this paper.