Development and validation of a sensitive UHPLC-MS/MS method for quantitative analysis of farrerol in rat plasma: Application to pharmacokinetic and bioavailability studies.

Farrerol is a 2,3-dihydro-flavonoid isolated from rhododendron. In this study, a sensitive and selective ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for the determination of farrerol in rat plasma. Liquid-liquid extraction by ethyl ether was used for sample preparation. Chromatographic separation was achieved on an Agilent UHPLC XDB-C column (2.1 × 100 mm, 1.8 μm) with water and methanol (30:70, v/v) as the mobile phase. An electrospray source was applied and operated in negative ion mode; selection reaction monitoring was used for quantification using target fragment ions m/z 299 → 179 for farrerol and m/z 267 → 252 for internal standard. Calibration plots were linear in the range of 2.88-1440 ng/mL for farrerol in rat plasma. Intra- and inter-day precisions were <11.6%, and the accuracy ranged from -13.9 to 11.9%. The UHPLC-MS/MS method was successfully applied in pharmacokinetics and bioavailability studies of farrerol in rats.