Pharmacokinetics, urinary excretion and plasma protein binding of ofloxacin in water buffalo calves ( Bubalus bubalis )

摘要

Pharmacokinetics and urinary excretion of an intravenous dose of 5 mg.kg –1 ofloxacin were investigated in water buffalo calves. Plasma concentrations of ofloxacin were determined by high-performance liquid chromatography. Ofloxacin was rapidly distributed from the central to the peripheral compartment as evidenced by a short distribution half-life (0.09 h ± 0.003 h) and high K 12 (4.7 h –1 ± 0.1 h –1 ), and was detected in plasma for 8 h. The large volume of distribution (2.48 L.kg –1 ± 0.18 L.kg – 1 ) obtained in this study indicated high distribution of ofloxacin in water buffalo calves. The elimination half-life, the area under the plasma drug concentration–time curve and total body clearance were 2.11 h ± 0.13 h, 6.20 μg.mL —1 ± 0.23 μg.mL —1 .h and 0.81 mL.kg –1 .h –1 ± 0.03 mL.kg –1 .h –1 , respectively. About 18.7% of administered drug was bound to plasma proteins and approximately 32.5% of the administered dose was recovered in urine within 48 h. The results of the study indicated a favourable pharmacokinetic profile of ofloxacin in water buffalo calves, which suggests that ofloxacin may be effective against urinary pathogens in this species.