Construction of propolis flavonoids-phospholipid complex loaded O/W submicron emulsion for enhancing in-vivo dilution stability and gastrointestinal absorption efficiency

Although numerous propolis flavonoids (EEP) formulations have been developed as dietary supplements for assisting blood glucose regulation, their bioavailability and bioactivity are limited due to the lower solubilities in aqueous media. To address this challenge, a novel O/W submicron emulsion was constructed to efficiently deliver propolis flavonoids and improve the absorption efficiency. Results showed that this delivery vehicle exerted inspiring features of nano-scaled droplet size, narrow particle distribution and higher cargo loading efficiency. Compared to conventional preparations, EEP submicron emulsion exhibited excellent stability against dilution with different pH buffers and maintained physicochemical characteristics within six months. Most importantly, EEP submicron emulsion could be efficiently absorbed through gastrointestinal (GI) tract via multiple-uptake routes and dramatically enhanced the bioavailability of propolis flavonoids. In conclusion, O/W submicron emulsion is a promising carrier for improving the in vivo utilization efficiency of water-insoluble flavonoids in functional foods.