A Critical Review of Properties of Modafinil and Analytical, Bioanalytical Methods for its Determination

Modafinil is a synthetic molecule used for the treatment of narcolepsy. Narcolepsy is a neurological disorder, due to which people experience frequent excessive daytime sleepiness (EDS). Nevertheless, there are some concerns about modafnil quality control. The modafinil enantiomers are both biologically active. However, it has been reported that the pharmacological properties of the both enantiomers are different and that the S-enantiomer is eliminated three times faster than the R-enantiomer. Therefore, most of the pharmaceutical companies have shifted to produce armodafinil (R-enantiomer) instead of the racemate. This article discusses about the critical review of the literature, the impact of the use of modafinil in the treatment of narcolepsy patients and other diseases, its physicochemical properties, toxicological properties, synthetic methods, analytical and bioanalytical methods and challenges that remain in order to ensure the quality. This article mainly focused on review of process related impurities, enantiomeric separation, metabolites of modafinil in various biofluids and pharmaceutical formulations using HPLC, LC-MS, GC-MS, CE, HPTLC and spectrophotometric methods.