A natural polysaccharide exudate guar gum was modified via graft copolymerization reaction aided by microwave irradiation. The graft copolymerization was carried out by using 2-hydroxyl ethyl methacrylate (PHEMA) as monomer and ceric ammonium nitrate (CAN) as a free radical initiator under microwave irradiation. Different grades of graft copolymers of (GG-g-P(HEMA)) were designed by varying the initiator and monomer concentrations and the best grade was developed with maximum percentage of grafting. The validation of synthesis was done by different characterization techniques such as C NMR, FTIR, SEM, CHNSO and TGA. These grades were applied as pH sensitive drug delivery carrier with pH variations in simulation with environment of gastrointestinal tract. The swelling study of GG-g-P(HEMA) based tablets was recorded as a function of varied pH and temperature to suit its application in GI tract. The equilibrium swelling percentage was found to be low at pH 1.2 whereas it was high at alkaline pH 7.4 condition. This swelling behavior makes this material quite suitable to be used as drug delivery carrier. The release mechanism of drug 5 - amino salicylic acid (5-ASA) was studied by different mathematical kinetics models. 5-ASA is a therapeutic drug to cure mild to moderate inflammatory bowel disease.