UPLC–MS/MS method for determination of avicularin in rat plasma and its application to a pharmacokinetic study

• This is the first report of the determination of avicularin level in rat plasma using an UPLC–MS/MS method.
• Sample preparation was accomplished with a simple one-step precipitation of plasma protein by acetonitrile–methanol (9:1, v/v).
• Only 1.6 min was needed for an analytical run.
• The method meets the requirement of high sample throughput in bioanalysis.

A rapid, sensitive and selective ultra-performance liquid chromatography tandem mass spectrometry (UPLC–MS/MS) was developed and validated for the determination and pharmacokinetic investigation of avicularin in rat plasma. Sample preparation was accomplished through a simple one-step deproteinization procedure with 0.2 mL of acetonitrile–methanol (9:1, v/v) to a 0.1 mL plasma sample. Plasma samples were separated by UPLC on an Acquity UPLC BEH C18 column using a mobile phase consisting of acetonitrile–0.1% formic acid in water with gradient elution. The total run time was 1.60 min and the elution of avicularin was at 1.20 min. The detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction-monitoring (MRM) mode using the respective transitions m/z 434.1 → 301.3 for avicularin and m/z 237.2 → 194.3 for carbamazepine (IS), respectively. The calibration curve was linear over the range of 10–3000 ng/mL with a lower limit of quantitation (LLOQ) of 10 ng/mL. Mean recovery of avicularin in plasma was in the range of 84.2–89.5%. Intra-day and inter-day precision were both <12%. This method was successfully applied in pharmacokinetic study after intravenous administration of 5.0 mg/kg avicularin in rats.