Single intravenous and oral dose pharmacokinetics of florfenicol in the channel catfish (Ictalurus punctatus)

Gaunt, P. S., Langston, C., Wrzesinski, C., Gao, D., Adams, P., Crouch, L., Sweeney, D., Endris, R. Single intravenous and oral dose pharmacokinetics of florfenicol in the channel catfish (Ictalurus punctatus). J. vet. Pharmacol. Therap. 35, 503-507. Plasma distribution and elimination of florfenicol in channel catfish were investigated after a single dose (10 mg/kg) of intravenous (i.v.) or oral administration in freshwater at a mean water temperature of 25.4 degrees C. Florfenicol concentrations in plasma were analyzed by means of liquid chromatography with MS/MS detection. After i.v. florfenicol injection, the terminal half-life (t1/2), volume of distribution at steady state (Vss), and central volume of distribution (Vc) were 8.25 h, 0.9 and 0.381 L/kg, respectively. After oral administration of florfenicol, the terminal t1/2, Cmax, Tmax, and oral bioavailability (F) were 9.11 h, 7.6 mu g/mL, 9.2 h, and 1.09, respectively. There was a lag absorption time of 1.67 h in oral dosing. Results from these studies support that 10 mg florfenicol/kg body weight in channel catfish is an efficacious dosage following oral administration.