ABSORPTION, DISTRIBUTION AND ELIMINATION OF OXOLINIC ACID IN ATLANTIC SALMON (SALMO-SALAR L) AFTER VARIOUS ROUTES OF ADMINISTRATION

Elimination half-life (t1/2,tau) of oxolinic acid (OA) in Atlantic salmon was estimated to be 60.3 h after a single rapid intravascular (i.v.) injection of 20 mg OA kg-1 body weight through a cannula into the dorsal aorta. Apparent volume of distribution (V(d)(ss)) was estimated to be 1.8 1 kg-1 and total clearance (Cl(T)) was 0.7 1 24 h-1 kg-1. Peak serum concentration (C(max) was achieved within 1 h and the mean bioavailability of OA was 47% after injection of 20 mg OA kg-1 body weight into the peritoneal cavity. After oral administration of 10 mg OA kg-1 body weight, C(max) was achieved after 3.9 h while mean bioavailability was 25%. All the fish were kept in seawater at 9.0-degrees-C. Repeated blood samples were taken via the cannula and serum was analysed by reversed-phase high-performance liquid chromatography.