Determination of calycosin‐7‐ O ‐ β ‐ d ‐glucopyranoside in rat plasma and urine by HPLC

A reversed‐phase high‐performance liquid chromatographic (HPLC) assay for calycosin‐7‐ O ‐ β ‐ d ‐glucopyranoside in rat plasma and urine with solid‐phase extraction (SPE) was developed. Rutin was employed as an internal standard. The mobile phase consisted of acetonitrile–water (16:84, v/v) at a flow rate of 1.0 mL/min. Detection was set at 280 nm. The limit of quantitation of calycosin‐7‐ O ‐ β ‐ d ‐glucopyranoside was 0.2 µg/mL in both plasma and urine. The standard curve was linear from 0.2 to 10.0 µg/mL in plasma, and 0.2 to 5.0 µg/mL in urine. Both intra‐ and inter‐day precision of the calycosin‐7‐ O ‐ β ‐ d ‐glucopyranoside were determined and their RSD did not exceed 10%. The method was successfully applied to the analysis of samples obtained from a basic pharmacokinetic study, in which calycosin‐7‐ O ‐ β ‐ d ‐glucopyranoside was administered orally to rats. Copyright © 2007 John Wiley & Sons, Ltd.