TISSUE CONCENTRATIONS AND PHARMACOKINETICS OF FLORFENICOL IN BROILER-CHICKENS

1. Florfenicol (30 mg/kg body weight) was administered to broiler chic kens via intravenous (iv), intramuscular (im) and oral routes to study its plasma concentrations, kinetic behaviour, systemic bioavailabilit y and tissue content. 2. Following a single iv injection, the kinetic disposition of flortenicol followed a 2-compartmental open model with an elimination half-life of 173 min, total body clearance of 26.9 ml/k g/min and a steady state volume of distribution of 5.11 l/kg. 3. The h ighest plasma concentrations of florfenicol were 3.82 and 3.20 mu g/ml following single im and oral administration, respectively. The system ic bioavailability was 96.6% and 55.3% after im and oral administratio n. The plasma protein binding of florfenicol was 18.5%. 4. Following i ts administration, the highest tissue concentrations of the drug were found in tile kidney bile, lung, muscle, intestine, heart, liver, sple en and plasma. Loll concentrations of the drug were found in brain, bo ne marrow and fat. No florfenicol residues were detected in tissues an d plasma after 72 h except in the bile from where it disappeared after 96 h.