Abstract: Pharmacokinetics and bioavailability of Catechin were studied in 10 healthy rabbits following single intravenousinjection (25mg/kg) and oral administration (25mg/kg) of the drug. The cateshin concentrations in plasma was determined byhigh-performance liquid chromatography. The concentration-time data were fitted to two-compartment open model followingsingle intravenous injection in rabbits. The main pharmacokinetic parameters were as follows: distribution half-life(t1/2α)(0.15±0.01)h, elimination half-life(t1/2β)(0.58±0.02)h, apparent distribution volume(Vd)(2.97±0.11)L total body clearance(ClB)(3.53±0.10) L/h and the area under curve(AUC) (16.95±1.52)mg/(L•h). The drug concentration-time data were fitted tosingle compartment open model after a single oral administration.The pharmacokinetic parameters were as follows:absorptionhalf-life (t1/2Ka) (0.39±0.06) h,elimination half-life (t1/2Ke) (0.79±0.11) h,peak time (tmax) (0.78±0.110h,peak concen-tration (Cmax) (3.35±0.16)mg/L,AUC (7.45±0.94), and bioavailability (F) 64±7.00%. The results showed that thepharmacokinetic characteristics of Catechin in health rabbits were rapid absorption,short time to reach the peak,fastelimination,short half-life, and large apparent distribution volume and not complete oral absorption.

Key words: catechin, high-performance liquid chromatography, bioavailability, pharmacokinetics, rabbits