Pharmacokinetics of Florfenicol in E.coli Infected Broiler Chickens

Pharmacokinetics of florfenicol was studied on experimentally E.coli infected broiler chickens following single intravenous(i.v.) and oral administration at a dose of 30 mg·kg -1.The kinetic disposition followed a 2-compartmental open model after a single i.v. injection in E.coli-free(control) and E.coli-infected broilers with weight by 1/C 2.The main pharmacokinetic parameters of florfenicol in healthy and infected broilers were as follows:t 1/2α 44.67±9.42 and 40.79±9.90,t 1/2β 161.02±27.30 and 118.91±14.17,Vd (ss) 1.15±0.41 and 1.02±0.22 L·kg -1,Cl B 0.73±0.12 and 0.76±0.14 L·kg -1·h -1,AUC 41.65±6.94 and 40.88±6.03 mg·L -1·h,respectively.The pharmacokinetic parameters of florfenicol in diseased broiler chickens significanly increased in β(P0.01),K 21(P0.05) and K 10(P0.01),significantly decreased in t 1/2β(P0.01).However,no significant difference occurred in other parameters(P0.05).Following single oral administration in E.coli infected broilers,florfenicol concentration-time data in plasma were fitted to the one-compartment open model.The main pharmacokinetic parameters in infected broilers were as follows:t 1/2ka 25.49±14.04 min,t 1/2ke 104.31±14.55 min,t max 65.91±26.24 min,C max 7.90±3.00 mg·L -1,AUC 29.01±6.59 mg·L -1·h,F 70.94±1.09%.As a result,the pharmacokinetic characteristics of florfenicol were distributed quickly,widely and eliminated rapidly.After oral administration in E.coli infected broilers,florfenicol had relatively higher value of system bioavailability.