Pharmacokinetics of marbofloxacin following intramuscular administration at different doses in sheep

The pharmacokinetics of marbofloxacin (MBX) was determined following the intramuscular administration at the doses of 2, 4, 6, and 10 mg/kg in twenty-four healthy sheep. In parallel design, sheep were randomized to 2, 4, 6, and 10 mg/kg dose groups of six animals per group. High performance liquid chromatography method for determination of MBX in sheep plasma was used. Pharmacokinetic parameters were calculated by a non-compartmental method. The dose-normalized the area under the concentration-versus-time curve (AUC(0-infinity)) and dose-normalized maximum plasma concentration (C-max) in 10 mg/kg dose group were significantly higher than other dose groups. The elimination half-life (t(1/2 lambda z)) of marbofloxacin in 10 mg/kg dose group was significantly longer than other dose groups. MBX exhibited dose-proportional pharmacokinetics and was well tolerated after 2, 4, 6 and 10 mg/kg doses in sheep. The 2, 4, 6, and 10 mg/kg doses of MBX could be administered in the treatment of infections caused by susceptible pathogens in sheep. However, additional studies are needed to identify whether MBX is efficient in sheep of naturally infected with susceptible bacteria.