Metabolism of [(14)C]flusilazole in the goat

[Phenyl(U)-(14)C] and [triazole(3)-(14)C]flusilazole ([(bis 4-fluorophenyl)]methyl(1H-1,2,4-triazole-1-ylmethyl)silane; I) were extensively metabolized when fed to lactating goats (Capra hircus). The primary metabolites identified in goat tissues and milk were bis(4-fluorophenyl)(methyl)silanol (II) and 1H-1,2,4-triazole (III). Concentrations of total radiolabeled residues in the milk ranged from 0.09 to 0.74 microg/mL. Concentrations of radiolabeled residues found in tissues when the [(14)C] label was in the phenyl or triazole position, respectively, were 13.5 and 3.54 microg/g (liver), 8.74 and 0.75 microg/g (kidney), 0.41 and 0.52 microg/g (leg muscle), and 4.07 and 0.94 microg/g (back fat). Urine contained an additional major metabolite identified as [bis(4-fluorophenyl)](methyl)silylmethanol (IV) and its glucuronic acid conjugate (V). With either labeled form of flusilazole, the majority of the recovered radiolabel was excreted in urine or feces.