LC Determination and Pharmacokinetic Study of Sinomenine in Dog Plasma

Abstract

A simple HPLC method has been developed for determination of sinomenine in dog plasma and has been used to evaluate the pharmacokinetics of sinomenine tablets in dogs. Chromatographic separation was performed on a reversed-phase column with 0.78% (w/v) NaH₂PO₄-acetonitrile, 88:12 (v/v), as mobile phase, delivered at a flow rate of 1.5 mL min⁻¹. Detection was performed at 265 nm. The limit of quantification was 5.0 ng mL⁻¹. The calibration range was from 5.0 to 1000 ng mL⁻¹. The developed method was applied to pharmacokinetic studies of sinomenine sustained-release tablets (test preparation) and sinomenine conventional tablets (reference preparation) in six dogs. Pharmacokinetic data t_max, C_max, AUC_0-t, AUC_0-∞, and t_1/2 for both preparations were determined from plasma concentration-time profiles. The method was sufficiently sensitive, simple, and repeatable for use in pharmacokinetic studies.