Enhanced dissolution rate and oral bioavailability of Ginkgo biloba extract by preparing solid dispersion via hot-melt extrusion

The aim of this study was to improve the dissolution rate and oral bioavailability of Ginkgo biloba extract (GBE) through the preparation of G. biloba extract solid dispersions (GBE-SD) via hot-melt extrusion (HME). First, we prepared the GBE-SD based on a Kollidon® VA64/Kolliphor® RH40 (85:15) spray dried powder. Then physicochemical properties were investigated by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and Fourier transform infrared spectroscopy (FT-IR). The results indicated that GBE dispersed well in a carrier matrix. Subsequently, we studied the dissolution profile of total flavonoids (TFs) by HPLC-UV and total terpene lactones (TTLs) by HPLC-ELSD. The dissolution percentage of TFs and TTLs was improved within 120 min. Finally, we studied the pharmacokinetic characteristics and bioavailability in rats by UPLC-MS/MS. The results showed that the Cmax and AUC0−t of bilobalide (BB), ginkgolide A (GA), ginkgolide B (GB), ginkgolide C (GC), quercetin (QCT), kaempferol (KMF) and isorhamnetin (ISR) in rats were significantly increased after the oral administration of GBE-SD compared with results after the oral administration of GBE. These results suggest that the solid dispersion preparation by HME could serve as a promising formulation approach to enhancing the dissolution rate and oral bioavailability of GBE.