Pharmacokinetics of thiamphenicol in chickens

The pharmacokinetics of thiamphenicol was investigated following single intravenous(i.v.),and oral administration at a dosage of 15 mg/kg and 30 mg/kg,respectively,in healthy chicken.20 chickens were randomly divided into two groups for the experiments.Blood samples were collected at different intervals after administration of thiamphenicol.The thiamphenicol in plasma was extracted with and de-proteined by ethyl acetate and its concentrations in plasma were determined by high performance liquid chromatography(HPLC) with a limit of detection of 0.01 mg/L.The concentration-time data of thiamphenicol in plasma were analyzed with pharmacokinetic-compartment analysis soft(3P97).The concentration-time data of marbofloxacin after i.v.administration were fitted to a two-compartment open model.The main pharmacokinetic parameters were as follows:V(c)(0.92±0.01) L/kg,t1/2α(0.27±0.02) h,t1/2β(3.46±0.74) h,AUC(11.67±0.57) mg/(L·h),CL(s) 1.29 L/(kg·h).The concentration-time data after oral adminstration were fitted to a one-compartment open model with first-order absorption.The main pharmacokinetic parameters were as follows:lagtime(0.043±0.01) h,t1/2ka(0.76±0.11) h,t1/2ke(2.16±0.58) h,T(peak)(1.73±0.11) h,C(max)(6.03±0.92) mg/L,AUC(32.43±0.75) mg/(L·h),F(138.58±0.07)%.The results showed that the pharmacokinetic characteristics of thiamphenicol in healthy chicken manifested the rapid and complete absorption,wide distribution,rapid elimination and the high bioavailability by the oral routes.