Disposition Kinetics of Enrofloxacin Following Intramuscular Administration in Goats

Enrofloxacin (enro) is a second generation fluoroquinolone that was specially developed for clinically use in veterinary practice. most of the previous studies on the pharmacokinetics of antibiotics have emphasized that the optimal therapeutic dosage of imported drugs should be determined in the local target species. so the present study was designed to determine the disposition kinetics of enro in healthy adult female goats under local environment. the enro was injected at 5 mg/kg through intramuscular route. after enro administration, blood samples were collected at different time intervals and analyzed through hplc. kinetic parameters were determined by subjecting the plasma concentration to the two compartment open model. the value of cmax and tmax were 1.03±0.101 μg/ml and 1.47±0.14 hours, respectively. the values of a and b were (1.46±0.25 and 0.99±0.10 μg/ml), respectively. the mean half-life values of absorption (t1/2 abs), distribution (t1/2α) and elimination (t1/2β) were 0.88±0.19, 0.69±0.10 and 2.84±0.30 hours, respectively. the values (mean±se) of vd and clb were 3.96±0.66 l/kg and 0.96±0.10 l/hr/kg, respectively. the priming and maintenance doses of enro after intramuscular administration based upon the minimum effective concentration c°p(min) were determined. the calculated priming dose for goats, at c°p(min) 0.05 μg/ml, was 4.49 mg/kg for 8 hour dosing intervals while the maintenance dose for corresponding dosing intervals was 4.29 mg/kg.