Metabolism, Distribution and Excretion of Ethanamizuril in Chickens

Abstract Ethanamizuril(N-{4-[4-(3,5-Dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-2-methyl-phenoxy]-phenyl}-acetamide, EZL) is a novel anti-coccidiosis compound and belongs to the class of triazines. In this study, the metabolism, distribution, and excretion of EZL were evaluated in chicken after administration of EZL at a single dosage. According to the relevant drug biotransformation rules, the exact molecular mass detection, the fragmentation characteristics and the retention times, a total of five metabolites were identified in vivo in chickens, including two phase I metabolites and three phase II conjugated metabolites. The major metabolic pathways of EZL in chickens were deacetylation, hydroxylation, and glucuronidation. Regarding 14C-tissue residues after administration, kidney was considered to be the target tissue, as 14C-tissue residues could be detected at 240 h post-dose. DeacetylEZL (M3) was the main metabolite, accounting for 68.65% and 25.62% of 14C in kidney at 6 h and 24 h, respectively. In h...