TISSUE CONCENTRATIONS AND PHARMACOKINETICS OF FLORFENICOL IN BROILER-CHICKENS

Florfenicol was once administered to broiler chickens via i. v., i. m. and oral route (30 mg/kg body weight) to study its plasma concentrati ons, kinetic behaviour, systemic: bioavailability and tissue levels. F ollowing a single i. v. injection, the kinetic disposition of florfeni col followed a two-compartmental open model with an elimination half-l ife of 173 min, total body clearance of 26.9 ml/kg/min and a steady st ate volume of distribution of 5.11 litre/kg. The highest plasma concen trations of florfenicol were 3.82 and 3.20 mu g/ml following single i. m. and oral administration, respectively. The systemic bioavailabilit y was 96.6 and 55.3 per cent after i. m. and oral administration. The plasma protein binding of florfenicol was 18.5 %. Following the admini stration, the highest tissue concentration of the drug was found in ki dney, bile, lung, muscle, intestine, heart, liver, spleen and serum. L ow concentrations of the drug were found in brain, bone marrow and fat . No florfenicol residues were detected in tissues and serum after 72 h except in the bile, it disappeared after 96 h.