Bioavailability of flumequine after oral administration to Atlantic salmon ( Salmo salar L.)

Abstract

The bioavailability of flumequine was investigated in Atlantic salmon ( Salmo salar L.) in seawater at 6–8 °C. Four types of commercially available medicated fish feed containing flumequine (5 g kg −1) were administered to different groups of salmons (dose: 25 mg kg −1 body weight). The drug was also given as an intravascular bolus injection (dose: 10 mg kg −1 b.w.) and in form of a suspension in water, fish oil or corn oil (dose: 25 mg kg −1 b.w.). Elimination half-lives of 30–40 h were found. The bioavailability of all the tested products was around 40%. Neither the absorption rate, the absorption pattern, nor the presence of feed seemed to have any influence on the bioavailability. The in vitro flumequine release from the medicated feed pellets was tested using a flow-through apparatus as described in the European Pharmacopoeia. A clear difference in dissolution profile among the four products was seen.