SALINOMYCIN RESIDUES AND THEIR IONOPHORICITY IN PIG-TISSUES

The effect of pretreatment with medicated feed on [14C] salinomycin residue levels in pig tissues was studied. Pigs were fed unmedicated feed or feed medicated with salinomycin at 41 ppm in the diet for 29 days and then dosed with [14C]salinomycin for 8 days. Total drug residue levels were below quantifiable limits of detection of kidney, fat, and muscle but at the tolerance limit of 1800 ppb for liver. In liver, pretreatment tended to lower total residue levels, and unchanged [14C] salinomycin accounted for <1% of the total drug residue. Approximately 15-20% of the total drug residue in liver was bound. Ionophoric activity in extracts of livers from the treated pigs was minimal, and only 2 of the 12 treated samples had ionophoric activity more than twice that obtained from the controls. © 1990, American Chemical Society. All rights reserved.