Characterization, release, and antioxidant activity of curcumin-loaded sodium alginate/ZnO hydrogel beads

In this study, we fabricated a series of novel sodium alginate/ZnO hydrogel beads to optimize the release profile of curcumin (Cur) and to avoid the burst release associated with pure hydrogels, which were used to mitigate the weaknesses of Cur, such as rapid physiological clearance and sensitivity to ultraviolet (UV) light and alkaline solutions. The results show that the composite hydrogel beads exhibit good pH sensitivity and controlled-release capacity, which could prolong the residence time of Cur in the gastrointestinal tract. After exposure to UV irradiation for 6 h, the 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging capacity of Cur-loaded hydrogel beads was decreased by only 13.70%, whereas that of pure Cur decreased by 62.04% under the same conditions; therefore, the encapsulated Cur showed a higher antioxidant activity. The composite hydrogel beads protected the Cur from light degradation and can therefore prolong the antioxidant activity of Cur. These results are beneficial for the design of delivery systems to entrap and control the release of unstable drugs.