LC–MS/TOF, LC–MSn and H/D Exchange Studies on Solifenacin Succinate Targeted to Characterize its Forced Degradation Products

Abstract

Solifenacin was subjected to hydrolysis (acidic, basic and neutral), photolysis, oxidation and dry heat stress conditions, as prescribed by International Conference on Harmonisation guideline Q1A (R2). The drug was found to be unstable under oxidative and photolytic stress, but was stable to hydrolysis and thermal degradation. In total, three degradation products were formed, which were resolved from the drug and each other on a C-18 column employing a gradient elution method. A complete mass fragmentation pattern of the drug was established with the help of mass spectrometry/time of flight and multi-stage tandem mass spectrometric data. The structures of degradation products were elucidated through comparison of their mass fragmentation patterns with the drug. A most plausible mechanistic explanation for drug degradation is proposed.