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 (Vdarea), volume of distribution at steady state (Vdss), area under curve (AUC) and clearance (ClB) 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.