Development of a gallic acid-loaded chitosan and polyvinyl alcohol hydrogel composite: Release characteristics and antioxidant activity.

The physico-chemical properties of a chitosan and polyvinyl alcohol (CS/PVA)-based hydrogel composite were investigated. Tetraethyl orthosilicate (TEOS) was employed as a crosslinking agent. The results indicated that the chitosan-based composite presented a thermal resistance up to 200°C. The structural properties, which were evaluated using FTIR and DSC, showed good miscibility between chitosan and polyvinyl alcohol. SEM presented a compact and homogeneous structure. The release profile of the chitosan-based hydrogel composite was investigated using gallic acid (GA). It showed high antioxidant activities, which were monitored using DPPH radical scavenging. Diffusion of water into the chitosan-based hydrogel was assumed to be pseudo-Fickian in PBS solution. The CS/PVA-based hydrogel composite exhibited good properties as a drug delivery system.