Synthesis and evaluation of pH-sensitive glycopolymers for oral drug delivery systems

Abstract

AbstractSucrose esters (SE) are surfactants with potential pharmaceutical applications because of their low toxicity, biocompatibility, and excellent biodegradability. Biodegradable and biocompatible copolymeric hydrogels based on glucose-6-acrylate-1, 2, 3, 4-tetraacetate (GATA) and methacrylic acid (MAA) were designed and synthesized. Because of the growing importance of sugar-based hydrogels as drug delivery systems, these new pH-responsive glucose-containing copolymeric hydrogels were investigated for oral drug delivery. The GATA monomer was synthesized and characterized. The copolymeric hydrogel was synthesized by free-radical polymerization. Azobisisobutyronitrile (AIBN) was the free-radical initiator employed and Cubane-1, 4-dicarboxylic acid (CDA) linked to two 2-hydroxyethyl methacrylate (HEMA) group was the crosslinking agent (CA) used for hydrogel preparations. The hydrogels were characterized by differential scanning calorimetry and FT-IR. Equilibrium swelling studies were carried out in enzyme-free simulated gastric and intestinal fluids (SGF and SIF, respectively). A model drug, olsalazine [3, 3-َazobis (6-hydroxy benzoic acid)] (OSZ) an azo derivative of 5-aminosalicylic acid (5-ASA), was entrapped in these gels and the in vitro release profiles were established separately in both enzyme-free SGF and SIF. The drug release was found to be faster in SIF. The drug-release profiles indicated that amount of drug release depends on their degree of swelling and crosslinking.