Pharmacokinetics of enrofloxacin in sheep following intravenous and intramuscular administration

A study was undertaken to evaluate the pharmacokinetics of enrofloxacin in female Muzzafarnagari sheep (1.5–2.5 year-old) following intravenous and intramuscular administration at a single dose of 5.0 mg/kg body weight. Plasma concentrations of enrofloxacin were determined by a high performance liquid chromatography. One and two compartment model adequately described plasma concentration time profile of enrofloxacin following single dose intramuscular and intravenous administration, respectively. The volume of distribution (Vd_area), volume of distribution at steady state (Vd_ss), area under curve (AUC) and clearance (Cl_B) were calculated as 6.94 L/kg, 7.23 L/kg, 8.24μg.h/ml and 0.67 L/kg/h, respectively following intravenous administration and 5.20 L/kg, 12.12 L/kg, 3.45μg.h/ml and 1.60 L/kg/h, respectively following intramuscular administration. The mean bioavailability (F %) of enrofloxacin following intramuscular administration was 45.621. Based on pharmacokinetic data, priming and maintenance dose of 6.8 and 6.1 mg/kg, respectively with the dosing interval of 24 h following intravenous administration, whereas 3.0 and 2.4 mg/kg, respectively following intramuscular administration at 12 h intervals was calculated in sheep.