Pharmacokinetics and bioavailability of a Ginkgo biloba extract

The aim of the present study was to assess the bioavailability of the main active ingredient in Ginkgo biloba extract, ginkgolid B. The study also focused on the pharmaco- kinetics of two different dosage regimens for orally administered Gingko biloba extract, 80 mg once daily and 40 mg twice daily for 7 days. Twelve healthy volunteers took part in the study. They were randomly assigned to one of the two treatment groups: 40 mg twice daily or 80 mg once daily, with an interval of 21 days between cycles. Statistical analysis was used to assess the main pharmacokinetic parameters. The results show that a dosage of 40 mg twice daily (every 12 hrs) is accompanied by a significantly longer half-life (t(1)/(2),) and mean residence time (MRT) than a single 80 mg dose, even though the latter causes a higher concentration peak (Cmax). The maximum concentration time (Tmax) is 2.3 hrs after administration in both treatments.