Pharmacokinetics Study of Rabdosia rubescens Drop Pills Based on UPLC-MS/MS

Abstract

Background: Rabdosia rubescens drop pills have the effects of clearing away heat and toxin, detumescence, relieving pain. Objective: A simple and sensitive method for simultaneous determination of oridonin, ponicidin, and rosmarinic acid in rat plasma was developed based on ultra performance liquid chromatography- tandem mass spectrometry (UPLC-MS/MS). Methods: Chromatographic separation was performed on a Waters ACQUITY UPLC BEH C18 column (2.1 × 100 mm, 1.7 μm) with a mobile phase consisting of water containing 0.2% formic acid (mobile phase A) and methanol (mobile phase B) at a flow rate of 0.3 mL/min over a total run time of 3.8 min. All analytes were measured with optimized multiple reaction monitoring (MRM) in positive and negative ion ESI mode. Results: The transitions of oridonin, ponicidin, rosmarinic acid, diphenhydramine, and chloramphenicol were 365.3→347.3, 363.3→345.2, 359.0→160.9, 256.0→167.2, and 321.1→151.9, respectively. The linear ranges were 1-256 ng/mL for ponicidin and rosmarinic acid and 2-512 ng/mL for oridonin. The validated method was stable and reliable. There was no significant difference in the half-life (t1/2) of the three analytes at three doses. The area under the curve (AUC0-t) and peak concentration (Cmax) of the three analytes decreased linearly in each dose range, and the linear correlation R2 of each analyte under the three doses was greater than 0.95. Conclusion: This method was successfully applied to pharmacokinetic studies of oridonin, ponicidin, and rosmarinic acid in rat plasma after intragastric administration of Rabdosia rubescens drop pills.