Separation and identification of degradation impurities of esomeprazole sodium

Drug impurities are important factors that affect drug safety and efficacy. The aim of this study is to separate and confirm the structure of two degradation impurities of esomeprazole sodium, designated X and Y. The impurities X and Y were successfully isolated using preparative HPLC by developing separation methods with the help of ACD/Labs AutoChrom software. There was a steady increase in X and Y impurities in forced esomeprazole sodium degradation. Impurity X was confirmed as 6‐methoxy‐1h‐benzo[d]imidazole‐2‐yl‐4‐amino‐3,5‐dimethylpyridinecarboxylate and impurity Y as 6‐methoxy‐1h‐benzo[d]imidazole‐2‐yl‐4‐hydroxy‐3,5‐dimethylpyridinecarboxylate using nuclear magnetic resonance spectrometry, infrared spectroscopy, and high‐resolution mass spectrometry. These findings provide a comprehensive understanding of the impurity profile of esomeprazole sodium because these impurities are reported for the first time. Based on our results, active pharmaceutical ingredient manufacturers can further control process parameters to reduce impurity generation, and drug production manufacturers can optimize the packaging and storage conditions of esomeprazole sodium.