Simultaneous determination of a novel anxiolytic agent buagafuran and one metabolite in human plasma by ultra-performance liquid chromatography-tandem mass spectrometry

► An assay for the simultaneous determination of buagafuran and one metabolite (M1) using UPLC-MS/MS was developed. ► The present method was validated according to FDA guidance. ► The method was applied to the PK studies of buagafuran after multiple oral dose administration in Chinese healthy volunteers. ► The linearity of the calibration curves was validated over the concentration range of 0.5-200 ng/mL.