Tissue distribution and elimination of florfenicol in topmouth culter (Culter alburnus) after oral administration

Abstract

The serum concentration and muscle residue of florfenicol following oral administration were evaluated in topmouth culter (Culter alburnus) under field conditions. Fishes were cultured in tanks and fed a commercial medicated diet containing 2000 mg/kg florfenicol in a single dose. The sampling was conducted at different intervals (0, 0.5,1,1.5, 2, 3, 4, 8, 10, 12, 16, 24, 36, 48, 72, 96, 120, 144, 168 h) after the cessation of medication. Drug analysis was carried out by HPLC. The maximum concentration (Cmax ) of 10.8 μg/g in serum and 4.2 μg/g in muscle were reached at the same time (t max ) of 8 hours. If the EU MRL value of 1.0 μg/g is quoted for the topmouth culter tissue, the extrapolation of the data indicated that it will be passed after a 40.6 h withdrawal period for florfenicol in topmouth culter muscle.