Stability-Indicating Methods for the Determination of Third-Generation Antiepileptic Drugs and Their Impurities

Between 2007 and 2018, many third-generation antiepileptic drugs, such as rufinamide, stiripentol, eslicarbazepine acetate, lacosamide, perampanel, brivaracetam, and everolimus, were authorised by international regulatory agencies. Numerous stability-indicating analytical techniques have been developed to identify these medications and their contaminants in order to assist their safety review. The physicochemical properties, impurity profiles, and analytical methods used for the identification and measurement of these compounds and their associated chemicals are summarised in this study. A comprehensive search of scientific literature and official pharmacopeias up to October 2020 identified a total of 56 analytical methods. These were primarily based on techniques such as HPLC, UPLC, HPTLC, GC, and UV/Vis spectrophotometry, with HPLC-UV being the most commonly used (approximately 70% of cases). Notably, several of these antiepileptic agents have limited data available regarding their stability and impurity profiling. The current state of research underscores the urgent need for further studies on the stability and safety of third-generation antiepileptic drugs to facilitate the development of robust pharmaceutical formulations.