ABSTRACT
Objective: To construct ginkgo flavonoids drug release system based on bioavailability of ginkgo flavonoids and its clinical drug delivery behavior. Methods: Suitable oil phase, surfactant and cosurfactant were selected according to the solubility; Suitable Km value (ratio of surfactant to cosurfactant) based on the pseudo-ternary phase diagram was selected by water titration; Further prescription studies were performed at the selected Km value; The microemulsion dose was determined by HPLC; The self-microemulsion was made according to the prescription, and then the appropriate materials were added to make pellets; The preparation of pellets was evaluated. Results: Isopropyl myristate (IPM), Tween 80 and anhydrous ethanol were selected as oil phase, surfactant and cosurfactant; The Km value was 3:1; The ratio of total quality of Tween 80 and absolute ethanol to IPM was 9:1; The size of particle was less than 30 nm; Drug loading was 13.32 mg/mL. Conclusion: The pellets are stable using microemulsion as the former preparation, which improve the bioavailability of flavonoids.
ABSTRACT
This study was aimed to investigate the dose-response relations and synergy effects of bioactive components in Ginkgo bilobaon antiplatelet aggregation and DPPH free radical scavenging.The antiplatelet aggregation experiment and DPPH free radical scavenging experiment were conducted respectively to investigate the dose-response relations and synergy effects.Firstly,the effect of inhibiting platelet aggregation induced by PAF of ginkgolides in rabbits was investigated.And then,the effect of DPPH free radical scavenging by ginkgo flavonoids was also investigated.Finally,the synergy effects among effective components were studied.The results showed that ginkgolide A,ginkgolide B,ginkgolide C and bilobalide had dose-response relations on antiplatelet aggregation.Quercetin,kaempferol and isorhamnetin had DPPH free radical scavenging effects with dose-response relation.It was concluded that ginkgolide had the dose-response relation on antiplatelet aggregation.Ginkgolide A and ginkgolide B had synergy effect.Ginkgo flavonoids had DPPH free radical scavenging effect.Quercetin and isorhamnetin had synergy effect.