Pharmacokinetic Studies of Enrofloxacin in Yak after Intramuscular Administration

The pharmacokinetic studies of enrofloxacin were investigated in yak (Bos grunniens L.) after administration of enrofloxacin by intramuscular route at 5 mgkg-1 body weight. Blood samples were collected from the jugular vein at predetermined time intervals after drug administration. Plasma was separated and analysed for enrofloxacin by reverse-phase high performance liquid chromatography. Various pharmacokinetic parameters were calculated using a non-compartmental model. The elimination half-life (t), area under plasma concentration-time curve (AUC), area under the moment curve (AUMC), mean residence time (MRT), apparent volume of distribution (Vd), total body clearance (ClB) and apparent first-order elimination rate constant (K) of enrofloxacin were 2.790.60 h, 5.351.29 ghmL-1, 21.508.60 gh2mL-1, 4.020.87 h, 3.760.83 Lkg-1, 935.09236.45 mLh-1kg-1 and 0.250.07 h-1, respectively after the administration of enrofloxacin. Because of faster elimination time, excellent tissue penetration, shorter half-life, low MRT after intramuscular administration of enrofloxacin at a dose rate of 5 mgkg-1, it is recommended for use in yaks at therapeutic dose.