Simultaneous Determination of Evodiamine and Rutaecarpine in Rat Plasma by UPLC-MS-MS and Its Application in a Pharmacokinetics Study

A rapid and robust ultra performance liquid chromatographic tandem mass spectrometric method was developed and validated for the simultaneous determination of evodiamine and rutaecarpine in rat plasma. The analytes were extracted from rat plasma by liquid–liquid extraction with ether. Analysis was carried out on an ACQUITY UPLC BEH C18 column with gradient elution. The analytes and the internal standard were detected without interference in the multiple reaction monitoring (MRM) mode. The calibration ranges of evodiamine and rutaecarpine were both 0.2–50 ng mL−1. The intra- and inter-day precisions were within +9.0 and +12.3%, while the accuracy was less than 3.8 and 5.8%, respectively. The method was successfully applied to the pharmacokinetics study of evodiamine and rutaecarpine in rats after oral administration of Wuzhuyu Tang.