Investigation of pH-sensitive galactopyranoside glycol hydrogels as effective vehicles for oral drug delivery

Abstract

Abstract High-loading-capacity pH-sensitive glycolhydrogels were developed using allyl α- D -galactopyranosideas a biodegradable and biocompatible carbohydrate. Thesenew pH-sensitive glycol polymers were obtained through thefree-radical polymerization of methacrylic acid and allyl α- D -galactopyranoside using 1,6-hexanediol diacrylate and 1,6-hexanediol propoxylate diacrylate as crosslinker. The novelsugar-bearing galactopyranoside-based hydrogels were ana-lyzed to test their hydrolytic behavior in vitro, consideringtheir potential application as drug delivery systems.Equilibrium swelling studies were carried out in enzyme-free simulated gastric and intestinal fluids (SGF and SIF;pH 8 and pH 1, respectively). A model drug, olsalazine (anazo derivative of 5-aminosalicylic acid), was entrapped inthese gels, and their in vitro release profiles were establishedseparately in SGF and SIF at 37 °C. The swelling and drugrelease profiles revealed that the amount of drug released andswelling of the hydrogels depended on the methacrylic acidcontent and the crosslinker type and content.Keywords Glycolhydrogel .Oraldrugdelivery .Methacrylicacid(MAA) .Allylα-