Pharmacokinetics and Bioavailability of Catechin in Rabbits

Pharmacokinetics and bioavailability of Catechin in rabbits following single intravenous(25 mg/kg) and oral(25 mg/kg)adiministration were studied by high performance liquid chromatography. The plasma drug concentration time curve was fitted to a two compartment model following a single intravenous injection in rabbits. The main pharmacokinetic parameters were as follows:distribution half life( t 1/2 α ) was (0.15±0.01)h,elimination half life( t 1/2 β ) was (0.58±0.02)h,apparent distribution volume( V d ) was (2.97±0.11)L, total body clearance( Cl B ) was (3.53±0.10)(L·h -1 ),the area under curve( AUC ) was (16.95±1.52) mg/(L·h).The drug concentration time curve was fitted to a one compartment open model after a single oral administration.The pharmacokinetic parameters were as follows: t 1/2 Ka =(0.39±0.06) h, t 1/2 Ke =(0.79±0.11) h, t max =(0.78±0.11) h, C max =(3.35±0.16) mg/L, AUC = (7.45 ±0.94)mg/(L·h),bioavailability( F )=(44.18±3.59)%. The results showed that the pharmacokinetic characteristics of Catechin in rabbits were absorbed rapidly, and in short time to reach C max , then fast elimination,short half life time and large apparent distribution volume. Oral absorption is not completed.