Pharmacokinetics of florfenicol and its major metabolite, florfenicol amine, in rabbits

• Published in: Journal of veterinary pharmacology and therapeutics Vol. 30; no. 1; pp. 32 - 36
• Main Authors: PARK, B.-K, LIM, J.-H, KIM, M.-S, HWANG, Y.-H, YUN, H.-I
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.02.2007; Blackwell Publishing Ltd
• Subjects: Administration, Oral; amines; Animals; Anti-Bacterial Agents - administration & dosage; Anti-Bacterial Agents - blood; Anti-Bacterial Agents - pharmacokinetics; Area Under Curve; bioavailability; Cross-Over Studies; drug evaluation; drug excretion; drug therapy; florfenicol; half life; Injections, Intravenous - veterinary; intravenous injection; Male; metabolites; oral administration; pharmacokinetics; rabbits; Rabbits - metabolism; Thiamphenicol - administration & dosage; Thiamphenicol - analogs & derivatives; Thiamphenicol - blood; Thiamphenicol - pharmacokinetics; veterinary drugs
• ISSN: 0140-7783; 1365-2885
• DOI: 10.1111/j.1365-2885.2007.00809.x

The pharmacokinetics of florfenicol and its active metabolite florfenicol amine were investigated in rabbits after a single intravenous (i.v.) and oral (p.o.) administration of florfenicol at 20 mg/kg bodyweight. The plasma concentrations of florfenicol and florfenicol amine were determined simultaneously by an LC/MS method. After i.v. injection, the terminal half-life (t₁/₂λz), steady-state volume of distribution, total body clearance and mean residence time of florfenicol were 0.90 ± 0.20 h, 0.94 ± 0.19 L/kg, 0.63 ± 0.06 L/h/kg and 1.50 ± 0.34 h respectively. The peak concentrations (Cmax) of florfenicol (7.96 ± 2.75 μg/mL) after p.o. administration were observed at 0.90 ± 0.38 h. The t₁/₂λz and p.o. bioavailability of florfenicol were 1.42 ± 0.56 h and 76.23 ± 12.02% respectively. Florfenicol amine was detected in all rabbits after i.v. and p.o. administration. After i.v. and p.o. administration of florfenicol, the observed Cmax values of florfenicol amine (5.06 ± 1.79 and 3.38 ± 0.97 μg/mL) were reached at 0.88 ± 0.78 and 2.10 ± 1.08 h respectively. Florfenicol amine was eliminated with an elimination half-life of 1.84 ± 0.17 and 2.35 ± 0.94 h after i.v. and p.o. administration respectively.