Metabolic Stability of a New Anticoccidial Drug Natromezuril in Rat Hepatic S9

A high performance liquid chromatograph(HPLC) method for measuring content of a new anticoccidial drug natromezuril after incubation with rat's liver S9 is established to study its metabolic stability and possible metabolites.The result demonstrated that drug concentration eliminated linearly in the first hour in the incubation system which accorded with the characteristics of primary reaction.Rate constant K was 0.004 719 min-1 and t1/2 was 146.88 min which illustrated natromezuril's high metabolic stability.Besides,a metabolite was detected in the system,the content of which increased as the elimination of natromezuril.We approximately estimated the metabolite accounts for 36% of metabolism of natromezuril.