Xanthan Gum Influence on Synthesis and Controlled Release from Sodium Acrylate Hydrogels

Abstract

This study investigates the synthesis, swelling behavior, and ascorbic acid (AA) release kinetics of sodium acrylate (SA)-xanthan gum (XA) hydrogels. Hydrogels were synthesized with varying XA concentrations (7%, 5%, 2%, and 0%) using potassium persulfate (KPS) or 2,2-azobis(2-methylpropionamide) dihydrochloride (V50) as initiators. Swelling was evaluated in aqueous media at room temperature, and AA was used as a model bioactive compound for release studies. Results showed that XA concentration influences swelling and release. Hydrogels synthesized with KPS exhibited minimal swelling variation, whereas those with V50 displayed concentration-dependent swelling. AA diffusion coefficients decreased with increasing XA concentration in V50-based hydrogels, suggesting a more controlled release. Swelling was pH-dependent, reaching a maximum under neutral conditions due to carboxyl group ionization. AA release in KPS hydrogels followed Fickian diffusion. These findings highlight the potential of XA-based hydrogels for controlled release applications, allowing optimization through XA concentration and synthesis conditions.