Studies On Pharmacokinetics And Residues Of Enrofloxacin Lactate Soluble Powder In Poultry

1. Pharmacokinetics study of enrofloxacin lactate: 24 healthy broilers with body weights of 1500g were randomly divided into 2 groups for orally administration and intravenous administration. The two groups were treated at a single dose of 10mg/kg body weight and the plasma were collected at different intervals after administration of enrofloxacin lactate; Plasma concentrations of enrofloxacin were determined by a high performance liquid chromatography (HPLC) with ultraviolet detector. The ci-ti data of enrofloxacin in plasma were analysed with 3p87 program. The results showed that the ci-ti data of enrofloxacin in plasma after orally administration in healthy broilers are fitted to a two-compart-ment model. The main parameters are as follows: t1/2(ka)(0.60±0.00)h,t1/2(ke)(8.25±1.73)h,tpeak(2.44±0.17)h,Cmax(1.44±0.30)mg/l,AUC(20.74±3.80)(mg/l) *h,F 87.54%.Pattens of decline of the plasma level of the drug in broilers after i.v. administration upon the body the characteristics of the two-compartment open model, and t1/2(ka)( 0.60±0.00)h,t1/2(ke)( 8.25±1.73)h,tpeak(2.44±0.17)h,Cmax(1.44±0.30)mg/l,AUC(20.74±3.80)(mg/l) *h,F 87.54%.2. The residue elimination of enrofloxacin lactate: 45 healthy broilers was administered enrofloxacin p.o. once per day at a dosage of 100mg/L for seven successive days. Five broilers per day were slaughtered at 0,1,3,5,7,9,11days after the last administration. Tissue sample preparations were carried out by adding a phosphate buffer (pH 7.4, 0.1 M), followed by extraction with trichloromethane.The residues of enrofloxacin and ciprofloxacin were determined by high performance liquid chromatography. Chromatographic analyses were carried out on a waters reversed-phase liquid chromatography systerm with fluorescence detector. emission wave length was 280 nm and excitation wave length was 450 nm. Chromatographic separation was performed on a Thermo ODS-2HYPERSIL C18 (5.0μm,250×4.6mm)column at a flow rate of 1 ml/min?1. And the raw data were analysed with WT1.4 program. Results of this experiment showed that the withdrawal period of lactate enrofloxacin in chicken was 8 days.