pH-Sensitive IPN Hydrogel Beads of Carrageenan-Alginate for Controlled Drug Delivery

Abstract

Interpenetrating polymer network (IPN) hydrogel beads of carrageenan-sodium alginate (Caralgi) were prepared under mild conditions. Betamethasone acetate, as a water-soluble drug model, was simultaneously loaded while the hydrogel network was being formed. The effect of pH and temperature of the preparative media on the drug loading efficiency was investigated. Maximum loading efficiency (71%) was achieved at pH 4.8 and 55°C. The chemical structure and morphology of the Caralgi IPN hydrogels with and without drug were studied using FTIR and SEM analyses. The system exhibited a loading efficiency that depended on the pH and temperature. The in vitro release behavior by Caralgi IPN samples, prepared under various conditions, was evaluated and compared with that of the non-IPN alginate-Ca 2+ and carrageenan-K + hydrogels at pH 1.2 and 7.4.