Self-microemulsifying sustained-release pellet of Ginkgo biloba extract: Preparation, in vitro drug release and pharmacokinetics study in beagle dogs

Abstract Ginkgo biloba extract (GBE50), the fifth generation extract of Ginkgo biloba , has been widely used in clinical treatment. This study was aimed at developing self-microemulsifying drug delivery system sustained-release pellets (SMEDDS-SR pellets) to achieve sustained release and increased the oral bioavailability of GBE50. Solubility studies and Pseudo-ternary phase diagrams were investigated to optimize the suitable compositions of SMEDDS-SR pellets. The optimal formulation of GBE50-SMEDDS consisting of oil (16.7% MCT), surfactant (33.4% Cremophor EL35), cosurfactant (33.4% PEG 400) and drug (16.7% GBE50) was obtained. The GBE50-SMEDDS-SR pellets were prepared by mixing GBE50-SMEDDS with diluent agent (MCC), disintegration agent (PVPP) and coating material of ethyl cellulose (EC) using extrusion spheronization method. The Morphology study of GBE50-SMEDDS-SR pellets after dispersion in water revealed a spherical and homogeneous structure of droplets (51.6 ± 1.8) nm. The in vitro release data revealed the sustained-release effect of GBE50-SMEDDS-SR pellets. Pharmacokinetics study in beagle dogs after oral administration yielded relative bioavailability ( Fr ) of 160.24% and 236.18% for GBE50-SMEDDS and GBE50-SMEDDS-SR pellets, respectively. Collectively, these results indicated that the SMEDDS-SR pellets could be an effective delivery system to achieve sustained release and improved oral bioavailability of GBE50.