Enhanced oral bioavailability of oligomeric proanthocyanidins by a self-double-emulsifying drug delivery system.

The present study aims at the formulation and evaluation of solid self-double-emulsifying drug delivery system (SDEDDS) to increase the bioavailability of oligomeric proanthocyanidin (OPC). The formulation is prepared through two-step method and is able to form water-in-oil-in-water (W/O/W) double emulsions after diluted with aqueous medium while keeping the drug in inner water phase. Solid-state characterization is performed by DSC and X-ray powder diffraction. Furthermore, antioxidant capacity shows that OPC is preserved by the solid SDEDDS. OPC-SDEDDS exhibit sustained release of OPC under the conditions mimicking gastrointestinal tract. The result shows that bioaccessibility of OPC is improved after incorporating into SDEDDS formulation compared to pure drug. The proposed SDEDDS is a promising carrier strategy for delivering the hydrophilic compounds with low-oral bioavailability.