RP-LC Quantification and Pharmacokinetic Study of Iriflophenone 2-O-α-Rhamnopyranoside in Rat Plasma

Abstract

Iriflophenone 2-O-α-rhamnopyranoside (IP2R) is one of the main bioactive constituents of the leaves of Aquilaria sinensis (Lour.) Gilg, used in traditional Chinese medicines. A simple, rapid, and sensitive reversed-phase high-performance liquid chromatographic method has been developed for analysis of IP2R in rat plasma after intravenous administration. The analyte was extracted from plasma samples with methanol as deproteinization agent. Analysis was performed on an 250 mm × 4.6 mm i.d., 5-μm particle, C₁₈ column with a 8 mm × 4.6 mm i.d., 5-μm particle, RP-18 guard column; the mobile phase was acetonitrile–H₂O–acetic acid 22:78:0.01 (v/v) at a flow-rate of 1.0 mL min⁻¹. UV detection was at 289 nm. The calibration plot was linear in the range 0.01–33.33 μg mL⁻¹ (r = 0.9997, n = 5) in rat plasma. The lower limits of detection and quantification were 0.004 and 0.01 μg mL⁻¹. Intra-day and inter-day precision were 1.18–3.96 and 1.29–2.81%, respectively. Average extraction recovery from plasma was more than 95%. This assay method was successfully used to study the pharmacokinetics of IP2R in rats after a single dose of 25 mg kg⁻¹ by intravenous administration; the plasma concentration–time curve of IP2R conformed to a two-compartment open model.