Determination of chloramphenicol in tissues—problems with in vitro metabolism

Abstract

Residues of drugs and other chemicals used in meat production are covered by EEC Directives; compliance with such Directives requires sensitive analytical techniques for residues analysis. One such drug, chloramphenicol, is used in farm animals and is a potential problem for the residues analyst because it is metabolised rapidly. The cytochrome P₄₅₀ mediated metabolism occurs both in vivo and in vitro in tissues removed from the animal. It is shown here that chemical inhibition of cytochrome P₄₅₀ significantly increases the recovery of chloramphenicol from spiked liver samples. It is suggested that piperonyl butoxide, a potent cytochrome P₄₅₀ inhibitor, be used to inhibit the enzyme system during the determination of chloramphenicol.