Pharmacokinetics of marbofloxacin, after one bolus oral administration in buffaloes calves: Preliminary study

Abstract

Buffalo breeding system has a great economic importance in South-America, principally in marginal or sub-tropical lands. The therapeutic recommendations applied to a single ruminant species are extrapolated to others but important differences among those were recognized. Marbofloxacin bolus is indicated in the treatment of neonatal gastroenteritis caused by Escherichia coli, in calves (25-50kg). The aim of this study was determined the pharmacokinetic behaviour of marbofloxacin after oral administration, as bolus, following the label approved recommendations to cattle. One bolus (50 mg) was administered in two clinically healthy buffaloes (two days-old, 48-50kg). Plasma concentrations of the marbofloxacin were determined by a HPLC/u.v. method. After oral administration, the values obtained were: tmax=0.5-6h, Cmax= 1.19-0.04μg/mL, AUCt=1.57-0.38μg·h/mL and MRTt= 3.34-6.92h, for calves 1 and 2 respectively. Fluoroquinolones act by concentration dependant killing mechanism, so high plasma concentration initially is important. For this reason, the recommended dose of 1mg/kg is inadequate in buffaloes.