Therapeutic deep eutectic solvents assisted the encapsulation of curcumin in alginate-chitosan hydrogel beads

Alginate (ALG)-Chitosan (CHI) hydrogel beads have been broadly studied as vehicles for controlled drug delivery applications. However, encapsulation of poorly-water soluble compounds is somehow limited by the need to use emulsifying agents and/or organic solvents. This study aimed to encapsulate curcumin in ALG-CHI beads using as drug solubilizing vehicles deep eutectic solvents (DES). Using this approach hydrogel beads were successfully produced using extrusion-dripping method. The beads were vacuum-dried and freeze-dried which impairs their morphology, shape and dimensions features, as well as physicochemical properties. Vacuum-dried beads showed superior performance and were further evaluated as curcumin carriers for drug release control. The results indicated that swelling, degradation and in vitro release studies were influenced by the pH, highlighting the suitability of these systems for intestinal drug delivery. These outcomes indicate that the encapsulation of curcumin in pH-responsive ALG-CHI hydrogel beads using DES can be successfully accomplished, holding a great promise as encapsulation strategy of poorly water-soluble compounds for intestinal-targeted delivery of curcumin.