Natural polymers are considered high value polymeric materials because of their potential as biocompatible materials with medical applications. The chemical modification of natural polymers by grafting has received considerable attention in recent years because of the wide variety of monomers available. As the first part of a continued research on conversion of carboxymethyl cellulosesodium salt (CMC) to useful biopolymer-based materials, large numbers of carboxylic functional groups were introduced onto CMC by grafting with poly methacrylic acid (PMAA). The graft copolymerization reactions were carried out under microwave-radiation, bis-acrylamide as a cross-linking agent and persulfate as an initiator. 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). Due to the great difference in swelling ratio at pH 1 and 7.4 for P-4, this polymer appears to be good candidates for colon-specific drug delivery. This hydrogel converted to nano by freeze drying method and characterized by scanning electron microscopy, differential scanning calorimetry and FT-IR. Model drugs, 5-aminosalicylic acid (5-ASA) and olsalazine [3, 3َ-azobis (6-hydroxy benzoic acid)] (OSZ) as an azo derivative of 5-ASA, was entrapped in these nano and microparticles 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 indicate that amount drugs release depends on their degree of swelling, particle size of PBDs and crosslinking.