Development and Validation of an Analytical Method to Identify and Quantitate Novel Modafinil Analogs in Products Marketed as Dietary Supplements

Modafinil (brand name Provigil®) is a Schedule IV (U.S.) drug used for the treatment of narcolepsy and sleep disorders. It is also known to be used recreationally. Analogs of modafinil, including adrafinil, remain unapproved and/or unscheduled. The lack of scheduling has made these analogs a popular target for recreational use and inclusion in dietary supplements. However, the use of controlled substances (or their analogs) without the care of a physician presents a public health risk. Preliminary nontargeted analyses in our laboratory revealed the presence of adrafinil in several dietary supplements, highlighting the need for an analytical method to identify modafinil analogs in supplements. A liquid chromatography high resolution mass spectrometry (LC-HRMS) method was developed and validated to quantitate modafinil, plus four novel unscheduled modafinil analogs: adrafinil, CRL-40,940, CRL-40,941, and N-methyl-4,4-difluoromodafinil. This method was then applied to four samples of products marketed as dietary supplements collected via undercover purchase. These four products were marketed as nootropics or cognitive enhancers and labeled to contain adrafinil. Adrafinil was found in all four samples. The identification of modafinil analogs in this context is important so that consumers are not, knowingly or unknowingly, consuming these active pharmaceutical ingredients in products marketed as dietary supplements.