Development and validation of a rapid and sensitive LC-MS/MS method for the determination of polyphyllin II in rat plasma and its application in a pharmacokinetic study.

Polyphyllin II, a major steroidal saponin isolated from Paris polyphylla, exhibits significant pharmacological activities. In this study, a rapid and sensitive liquid chromatography-tandem mass spectrometry method was established and validated for the determination of polyphyllin II in plasma. Polyphyllin II and polyphyllin VII (internal standard) were separated on a Waters Acquity™ HSS T3 column and the mass analysis was performed in a triple quadrupole mass spectrometer equipped with an electrospray ionization ion source. Results showed that the method was sensitive (lower limit of quantitation 0.5 ng/ml), precise ( 0.99). Interestingly, the sensitivity in current study was ~10 times higher than that in the previous study. The results of the pharmacokinetic study of polyphyllin II in rats suggested that polyphyllin II was poorly absorbed into blood and reached its highest concentration at ~3.67-5.00 h with a slow elimination half-life of 8.34-13.37 h. The bioavailability was 6.1-8.2%. The results indicated that the absorption of polyphyllin II may primarily occur via passive diffusion in rats. This study provides valuable information that can be used as a reference for the pharmacokinetic investigation of other steroidal saponins.