ABSTRACT
Objective: To establish and determine the content of the genotoxic impurity piperidine in the active pharmaceutical ingredient (API) of rimonabant using a liquid chromatography-mass spectrometry (LC-MS) method. This study underscores the importance of detecting piperidine due to its potential health risks, including carcinogenic and mutagenic effects, thus highlighting the critical need for rigorous quality control in pharmaceutical products. Methods: An Atlantis C18 column (5 µm, 3.9×100 mm) was chosen for separation due to its high efficiency and selectivity for piperidine, with a gradient elution of 0.05% formic acid-water (A) and methanol (B) as the mobile phase at a flow rate of 1.0 mL/min. The column temperature was optimized at 30°C to ensure peak resolution and sensitivity, the injection volume was set to 5.0 µL to minimize sample consumption while maintaining detectability, and the analysis time was kept at 7 min for efficient throughput. Results: Piperidine demonstrated excellent linearity in the concentration range of 0.03-0.40 µg/mL (R>0.99), with a detection limit of 0.01010 µg/mL. This detection limit is significantly lower than regulatory thresholds, indicating the method's high sensitivity compared to existing methods and its adequacy for regulatory compliance in pharmaceutical quality control. Conclusion: This LC-MS method not only demonstrated high accuracy, good repeatability, and strong durability but also sets a benchmark for future research, regulatory practices, and pharmaceutical quality control. By accurately detecting low levels of genotoxic impurities like piperidine, this method supports the development of safer drug formulations and underscores the importance of stringent quality control measures in the pharmaceutical industry.