New pH-sensitive glycopolymers for colon-specific drug delivery.
pH-sensitive hydrogels are suitable candidates for oral delivery of therapeutic peptides, proteins, and drugs, due to their ability to respond to environmental pH changes. New pH-sensitive glycopolymers have been developed by free-radical polymerization of methacrylic acid and 6-acryloyl-glucose-1, 2, 3, 4-tetraacetate, using 1, 6-hexandiol diacrylate and 1, 6-hexandiol propoxylate diacrylate as cross-linking agents. The hydrogels were characterized by differential scanning calorimetry and FTIR. 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)] as an azo derivative of 5-aminosalicylic acid, was entrapped in these gels and the in vitro release profiles were established separately in both enzyme-free SGF and SIF. The drug-release profiles indicated that the amount of drug released depended on the degree of swelling. The hydrogels containing polar propoxylate groups were hydrolyzed rather easily.
Mahkam
M
M
Chemistry Department, Azarbaijan University of Tarbiat Moallem, Tabriz, Iran. mmahkam@yahoo.com
D000636:Aminosalicylic Acids / Q000008:administration & dosage / Q000737:chemistry; D001391:Azo Compounds / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D003106:Colon / Q000378:metabolism*; D003432:Cross-Linking Reagents; D016503:Drug Delivery Systems; D005609:Free Radicals; D020100:Hydrogels; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D019804:Mesalamine / Q000008:administration & dosage / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics
D000636:Aminosalicylic Acids; D001391:Azo Compounds; D003432:Cross-Linking Reagents; D005609:Free Radicals; D020100:Hydrogels; D011108:Polymers; D019804:Mesalamine; C032587:olsalazine