Development of a liquid chromatography–mass spectrometry method for determination of agrimol B in rat plasma: application to preclinical pharmacokinetics

A sensitive and accurate liquid chromatography coupled with mass spectrometry (LC‐MS) method was developed for the determination of agrimol B, a main active ingredient isolated from Agrimonia pilosa Ledeb., in rat plasma. Chromatographic separation was achieved on a Zorbax CN column (150 × 4.6 mm, 5 µm), with isocratic elution consisting of acetonitrile and water (15:85, v/v) at a flow rate of 0.6 mL/min. Agrimol B and dryocrassin ABBA, an internal standard (IS), were analyzed by selected ion monitoring at m / z transitions of 681.3 and 819.4, respectively. This assay exhibited a good linearity with a correlation coefficient >0.99 and showed no endogenous interference with the analyte and IS. The limit of quantification of agrimol B was 8.025 ng/mL with acceptable precision and accuracy. The method was successfully applied in the pharmacokinetic study of agrimol B in rats after intravenous (1 mg/kg) and oral (2, 5 and 10 mg/kg) doses of agrimol B. The absolute bioavailability of agrimol B was 16.4–18.0% in rat. Our study clarifies the pharmacokinetic behavior of agrimol B in animals. Copyright © 2014 John Wiley & Sons, Ltd.