Pharmacokinetics and Bioavailability of Roxarsone in Chickens

The pharmacokinetics of roxarsone was investigated by following single intravenous (i.v.) and oral administration both at a dosage of 10 mg/kg in healthy chickens. 24 chickens were randomly divided into two groups for experiments. Blood samples were collected at different intervals after administration of roxarsone. The concentrations of roxarsone in plasma were determined by high performance liquid chromatography (HPLC). Plasma concentration-time profiles of roxarsone were analyzed by using non-compartmental analysis WinNonlin 5.2 software. The main pharmacokinetic parameters of i.v. administration were as follows: t_1/2β=（2.37±0.11）h,V_z =（5.29±0.37）L·kg^-1,AUC_0-∞=（6.55±0.28）mg·L ^-1·h,CL=(1.56±0.07) L·h^-1·kg^-1. The main pharmacokinetic parameters of oral administration were as follows: t_1/2β=(3.02±0.08) h,t_max= (1.00±0.07) h,C_max= (1.09±0.08)mg·L^-1,AUC_0-∞=(2.30±0.10) mg·L^-1·h,MRT=(2.44±0.13) h,F =(35.28±1.0)%.The results showed that the pharmacokinetic characteristics of roxarsone in healthy chicken manifested wide distribution, rapid elimination as well as incomplete absorption and low oral bioavailability.