Gender difference in ranolazine pharmacokinetics in rats.

Pharmacokinetics of ranolazine (RAN) in both female and male rats was studied. RAN concentrations in plasma were determined after oral administration of 12.5, 25 and 50 mg/kg RAN. Concentrations in tissues, recoveries of RAN in urine and bile were also analyzed following oral dose of 25 mg/kg. It was found that plasma concentrations of RAN in female rats were significantly higher than those in male rats. Drug exposures based on Cmax and AUC in female rats were roughly 2-to 3-fold of those in male rats. Terminate half-life T1/2 and MRT in male rats were shorter than those in female rats. The recoveries in urine and bile of female rats were also markedly higher than those in male rats'. Tissue concentrations of RAN in female rats were also markedly higher than those in male rats. These results demonstrated existence of marked gender difference in RAN pharmacokinetics in rats.