Absorption, metabolism, and excretion of [14C]MK-0767 (2-methoxy-5-(2,4-dioxo-5-thiazolidinyl)-N-[[4-(trifluoromethyl)phenyl] methyl]benzamide) in humans

MK-0767 (KRP-297; 2-methoxy-5-(2,4-dioxo-5-thiazolidinyl)-N-[[4-(trifluoromethyl)phenyl] methyl]benzamide) is a thiazolidinedione (TZD)-containing dual agonist of the peroxisome proliferator-activated receptors alpha and gamma that has been studied as a potential treatment for patients with type 2 diabetes. The metabolism and excretion of [14C]MK-0767 were evaluated in six human volunteers after a 5-mg (200 microCi) oral dose. Excretion of 14C radioactivity was found to be nearly equal into the urine (approximately 50%) and feces (approximately 40%). Elimination of [14C]MK-0767 was primarily by metabolism, with minimal excretion of parent compound into the urine (<0.5% of dose) and feces (approximately 14% of the dose). [14C]MK-0767 was the major circulating compound-related entity (>96% of radioactivity) through 48 h postdose. It was also found that approximately 91% of the total radioactivity area under the curve was due to intact MK-0767. Several minor metabolites were detected in plasma (<1% of radioactivity, each), formed by cleavage of the TZD ring and subsequent S-methylation and oxidation. All the metabolites excreted into urine were formed by TZD cleavage, whereas the major metabolite in feces was the O-demethylated derivative of MK-0767.