Characterization of the major degradation products of the praziquantel API by mass spectrometry: Development and validation of a stability-indicating reversed phase UPLC method

Abstract Praziquantel was subjected to forced degradation studies under various conditions of hydrolysis (acidic, alkaline, and neutral/water), oxidation, photolysis, and thermal as prescribed by International Conference on Harmonization guideline Q1A (R2). A short and simple reversed phase UHPLC method was developed for the Praziquantel API. The method was developed on a Shimadzu, Shimpack Velox, SP-C18, 100 × 2.1 mm, 1.8 µm column. The isocratic mobile phase was a blend of water and acetonitrile in the ratio of 70:30 (v/v), respectively. The flow rate of the mobile phase was 0.5 mL/min. The developed method was validated using ICH guidelines. The parameters considered for method validation were solution stability, specificity, DL/QL, linearity, accuracy, precision, and robustness. The drug showed significant degradation in acidic and alkaline conditions while slight degradation was observed in water and oxidative conditions. The drug was found to be stable in photolytic and thermal conditions. The characterization of four major degradation products (DP1, DP2, DP3, and DP4) was done with LC–Q-TOF-MS/MS in combination with accurate mass measurements. The most probable mechanisms for the formation of DPs have been proposed on the basis fragmentation pattern. Graphical Abstract