Pharmacokinetic Profile of Matrine in Pigs Following Intravenous and Oral Administration

The search for effective alternatives or adjuncts to conventional anti-infective strategies in food animals has increased interest in plant-derived bioactive compounds. Matrine, a quinolizidine alkaloid derived from Sophora flavescens, has attracted considerable attention because of its broad bioactivities and potential veterinary relevance. Recent oral pharmacokinetic and intestinal-lumen PBPK studies in pigs have begun to emerge; however, currently available swine data remain largely confined to oral exposure-oriented experiments and do not permit direct route comparison or estimation of absolute oral bioavailability. In the present study, the plasma pharmacokinetics of matrine in pigs were evaluated after single-dose intravenous and oral administration. Twelve healthy piglets received matrine at 8 mg/kg body weight via either the intravenous or oral route, and plasma concentrations were quantified using a validated UPLC-MS/MS method. Pharmacokinetic parameters were estimated by non-compartmental analysis. Compared with intravenous administration, oral dosing produced lower observed exposure based on AUC0-t and a lower peak plasma concentration, with AUC0-t and Cmax values of 418.94 ± 75.52 h·ng/mL and 66.24 ± 8.44 ng/mL, respectively, versus 558.01 ± 59.57 h·ng/mL and 224.64 ± 20.94 ng/mL after intravenous administration. Oral administration was associated with a Tmax of 2.49 ± 0.02 h and a longer apparent terminal half-life and mean residence time than intravenous dosing. These findings provide pharmacokinetic evidence to support future route selection, dosing-regimen design, and PK/PD-based dose optimization of matrine in pigs.