Rice bran phospholipid-based nanovesicles for enhanced oral and topical delivery of capsaicinoids

The current work aimed to fabricate a rice bran phospholipid-based nanovesicular system for oral and topical delivery of capsaicinoids from Capsicum annuum. Using a modified thin film-hydration method, capsaicinoid-loaded nanovesicles (CLNVs) with encapsulation efficiency of 92.31 +/- 5.35% and a mean diameter of 134 +/- 2 nm, were produced. Based on in vitro release studies, the produced CLNVs exhibited a slow and limited release in both simulated salivary and gastric fluids, and selective release in simulated intestinal fluid, suggesting the opportunity for targeting release via the gastro-intestinal tract during oral delivery. Furthermore, the observed limited release of capsaicinoids in surfactant solution is a desirable property for topical delivery formulations. The fabricated delivery vehicle has also shown a masked and reduced irritation effect that co-occur with the strong anti-inflammatory activity of the capsaicinoids. Using a modified duck egg chorioallantoic membrane (CAM) assays, it was demonstrated that encapsulation into nanovesicles was able to reduce the irritancy of capsaicinoids by almost 50% and, at the same time, improve the anti-inflammatory activity by up to 10 folds. These results demonstrated the potential of CLNVs to be developed as oral and topical delivery systems for capsaicinoids.