Pharmacokinetics/Pharmacodynamics of Y‐700, A Novel Xanthine Oxidase Inhibitor, in Rats and Man

The pharmacokinetics and pharmacodynamics of a novel xanthine oxidase (XO) inhibitor, Y‐700, were evaluated in rats and healthy male volunteers. In a rat model of hyperuricemia, oral Y‐700 (0.3–10 mg/kg) showed a more potent and a longer‐lasting hypouricemic action than allopurinol. A single oral dosing of Y‐700 (5, 20 or 80 mg) to volunteers caused a dose‐dependent reduction of serum uric acid levels indicating close relationship to plasma concentrations of the compound. In addition, Y‐700 was hardly excreted in urine but mainly excreted in feces in rats and volunteers. These results suggested that Y‐700 is a new effective inhibitor of XO in rats and humans with high oral bioavailability being predominantly eliminated via the liver unlikely to allopurinol. †These authors equally contributed to this work.