Pharmacokinetics of bilobalide, ginkgolide A and B after administration of three different Ginkgo biloba L. preparations in humans

A sensitive LC-ESI-MS method with a solid-phase extraction was established for the determination of bilobalide, ginkgolide A and ginkgolide B in human plasma; bioavailability and pharmacokinetics of three different Ginkgo biloba L. preparations have been investigated. The preparations used in the present single-dose pharmacokinetic study were different formulations of Ginkgo biloba L. extracts (Geriaforce™ tincture, new Ginkgo fresh plant extract tablets and EGb 761™) with various excipients. The analysis of Ginkgo terpene lactones was performed by LC-MS on a Zorbax® SB-C18 column. The mobile phase consisted of water + 0.1% acetic acid and methanol 68/32 (v/v) to 49/51 (v/v) at a flow rate of 200 μL/min. Bilobalide, ginkgolide A and ginkgolide B were monitored using the selected-ion monitoring (SIM) mode at m/z of 325, 453 and 423, respectively. The amounts of the active compounds (terpene lactones) in the administered products were in the low-mg range per dose. The assay method was successfully applied to the study of the pharmacokinetics and bioavailability of bilobalide, gingkolide A and ginkgolide B in humans. The resulting maximum concentrations (median) of bilobalide, ginkgolide A and ginkgolide B in plasma after administration of the maximum daily dose of the different Ginkgo products were 3.53, 3.62, and 1.38 ng/mL respectively after administration of Geriaforce™ tincture; 11.68, 7.36, and 4.18 ng/mL, respectively after taking Ginkgo fresh plant extract tablets; and 26.85, 16.44, 9.99 ng/mL, respectively after administration of EGb 761™ tablets. These data are relevant to demonstrate relative bioavailabilities of different Ginkgo biloba L. preparations (Geriaforce™ tincture, new Ginkgo fresh plant extract tablets and EGb 761™). Copyright © 2009 John Wiley & Sons, Ltd.