SINGLE-DOSE CROSSOVER STUDY TO EVALUATE THE ABSOLUTE BIOAVAILABILITY OF A SUSTAINED-RELEASE FORMULATION OF BUNAZOSIN (E1015) IN HEALTHY MALE-VOLUNTEERS

An open-label randomised crossover study was undertaken to investigate the pharmacokinetics of intravenous bunazosin, and to determine the a bsolute bioavailabilities of the standard and sustained-release tablet formulations of the drug. 12 healthy volunteers received a 10-minute intravenous infusion of bunazosin 1mg, 2 conventional sugar-coated bun azosin 1mg tablets, and a sustained-release bunazosin 6mg tablet under fasting conditions. Plasma bunazosin concentrations declined in a bie xponential manner following intravenous drug administration, and simil ar terminal elimination half-lives (almost-equal-to 2 hours) were obse rved with intravenous bunazosin and the conventional tablet. The absol ute bioavailabilities of the conventional and sustained-release tablet formulations of bunazosin were 44.1 +/- 7.7 and 44.6 +/- 10.6%, respe ctively (mean +/- SD).