A validated LC-MS/MS assay for the simultaneous determination of periplocin and its two metabolites, periplocymarin and periplogenin in rat plasma: Application to a pharmacokinetic study.

A sensitive and reliable LC-MS/MS method was developed and validated for the simultaneous determination of periplocin and its two metabolites (periplocymarin and periplogenin) in rat plasma using psoralen as the internal standard (IS). After liquid-liquid extraction with ethyl acetate, chromatographic separation was performed on a C18 column with a 13 min gradient elution using 0.1% formic acid and acetonitrile as mobile phase at a flow rate of 0.3 mL/min. The detection was accomplished on a tandem mass spectrometer via an electrospray ionization (ESI) source by multiple reaction monitoring (MRM) in the positive ionization mode. The lower limits of quantitation (LLOQs) for periplocin, periplocymarin and periplogenin were 0.5, 1 and 0.1 ng/mL, respectively. The mean recoveries of the analytes and IS were higher than 67.7%. The proposed method was successfully applied to evaluating the pharmacokinetic studies of periplocin and its metabolites (periplocymarin and periplogenin) in rats after a single oral administration of periplocin at 50 mg/kg.

A validated LC-MS/MS method for determination of periplogenin in rat plasma and its application in pharmacokinetic study.

A method coupling high performance liquid chromatography with tandem mass spectrometry has been developed and validated for quantifying periplogenin in rat plasma using psoralen as an internal standard (IS). Plasma samples were pretreated using a simple liquid-liquid extraction with ethyl acetate and the chromatographic separation of periplogenin and psoralen was achieved on a Waters XBridge™ BEH C18 column with 0.1% formic acid and acetonitrile as mobile phase at a flow rate of 0.4mL/min. The detection was performed on a positive ion mode with electrospray ionization (ESI) source. The optimized ion transition pairs for quantitation were m/z 391.3→m/z 337.2 for periplogenin and m/z 187.0→m/z 131.0 for IS. The total run time was 9.0min. The calibration curve was linear over the range of 0.2-250ng/mL (r>0.99) with the lower limit of quantitation (LLOQ) at 0.2ng/mL. The intra- and inter-day precision were below 9.85% and the mean accuracy were from -10.03% to 10.26%. The average recoveries of periplogenin in plasma ranged from 85.1% to 95.6%. The proposed method was successfully applied in evaluating the pharmacokinetics of periplogenin after an oral dose of 30mg/kg Cortex Periplocae extract in rats.