Pharmacokinetic Behaviour of Marbofloxacin in Normal and Mycoplasma gallisepticum infected Chickens

Abstract

The pharmacokinetics of marbofloxacin in normal and Mycoplasma gallisepticum experimentaly infected broiler chickens was investigated after I.V. and oral administrations at a dose of 5 mg/kg.b.wt. Moreover, tissue residues in normal chickens after successive daily oral administration were also investigated. Plasma concentrations and tissue residues of marbofloxacin were determined by using high-performance liquid chromatography. The results showed that plasma concentrations were significantly higher in normal than in infected chickens following intravenous and oral administration. Marbofloxacin was eliminated after intravenous injection with half life (t1/2 β) of 6.8 ± 0.34h in normal which significantly longer than 5.66±0.33 in infected. The mean residence time was 9.67±0.5 h in normal vs 8.03±0.45 h in infected chickens. After oral administration the drug reached its maximum plasma concentrations (cmax) of 1.37±0.08 μg/ml at maximum time (tmax) of 1.95±0.04h in normal, while in diseased chickensn the cmax 0.95±0.02 μg/ml attained at tmax of 2.08±0.05h in diseased chickens. Following repeated oral administration of marbofloxacin at adose of 5 mg /kg.b.wt once daily for 3 consecutive days, marbofloxacin was detected after 24 h of the last dose at mean concentration of 1.52