Preparation of polymeric prodrugs based on 2-hydroxy propyl methacrylate containing 5-aminosalicylic acid drug

Inflammatory Bowel Diseases (IBD), which include ulcerative colitis and Crohn’s disease, are chronic inflammatory bowel diseases of unknown etiology [1]. 5-Aminosalicylic acid (5-ASA) is widely accepted in treatment of IBD, including ulcerative colitis and Crohn’s disease [2]. In this work, first 5-ASA was refluxed in formic acid and added cold distilled water to obtain 5-formylaminosalicylic acid as a white precipitate. The precipitate was filtered, washed several times with cold water, and dried in vacuum. 5-formylaminosalicylic acid was linked to 2-hydroxypropyl methacrylate by carbodiimidazole (CDI) to obtain metachryloyloxy propyl 5-amino salicylate. The resulting acrylic derivative of 5-ASA was copolymerized with 2-hydroxypropyl methacrylate and methyl methacrylate by free radical polymerization method in DMF solution at 70 °C. The obtained polymers were characterized by FT-IR, 1HNMR, elemental analysis and gel permeation chromatography. Release studies of 5-amino salicylic acid were performed into dialysis bags by hydrolysis buffered solutions in different pH at 37 °C. Detection of hydrolysis by UV spectroscopy at selected interval showed that the drug can be released by selective hydrolysis of the ester bond at the side of drug moiety .The release profiles indicated that the hydrolytic behavior of polymeric prodrugs is strongly based on the hydrophobicity of polymer and the pH of the hydrolysis solution.