Product Information

• Product Number: E001051

• English Name: Esomeprazole Impurity 51

• English Alias: 5-hydroxy-1H-benzo[d]imidazole-2(3H)-thione

• CAS Number: 92806-98-9

• Molecular Formula: C?H?N?OS

• Molecular Weight: 166.20

Advantages

• Well-defined and highly characteristic structure: A unique structure containing hydroxyl, benzimidazole ring and thione group, significantly different from the benzimidazole sulfonyl structure of Esomeprazole. It can be accurately identified by techniques like HPLC and LC-MS, providing a specific marker for impurity detection;

• High stability and traceability: The benzimidazole ring and thione group are relatively stable under neutral conditions. As a potential by-product of thiol oxidation or cyclization in Esomeprazole synthesis, it directly reflects the conversion efficiency of sulfur-containing intermediates, improving the accuracy of process tracing;

• High detection sensitivity: The conjugated structure of hydroxyl and benzimidazole ring has strong absorption in the UV region (around 280nm), enabling trace analysis via HPLC-UV, reducing detection costs and enhancing method applicability.

Applications

• Pharmaceutical quality control: Used as an impurity reference standard to identify and quantify Esomeprazole Impurity 51 in Esomeprazole APIs and formulations, ensuring residual sulfur-containing impurities meet pharmacopoeial and regulatory requirements;

• Synthesis process optimization: Reducing thione by-product formation by monitoring the impurity content and optimizing the dosage of thiol oxidants (e.g., hydrogen peroxide) to improve main product yield;

• Stability studies: Investigating the degradation behavior of this impurity under acidic conditions (e.g., thione hydrolysis) to assess its impact on Esomeprazole formulation stability and support storage condition development.

Background Description

Research Status

• Detection method optimization: Using UPLC-MS/MS technology to optimize mass spectrometry parameters based on the isotopic characteristics of sulfur, achieving trace detection of this impurity (detection limits up to ppb level);

• Synthetic mechanism analysis: Clarifying the formation pathway of this thione impurity by simulating cyclization reactions under different pH conditions, providing a theoretical basis for process optimization;

• Stability assessment: Studying the conversion trend of this impurity under high temperature and humidity through accelerated experiments to evaluate its impact on the shelf life of Esomeprazole formulations;

• Toxicological research: Assessing the potential cytotoxicity of this impurity through in vitro cell experiments to provide data support for formulating reasonable impurity limit standards