The purpose of the present study was to design and evaluate an Oral, site specific, Pulsatile drug delivery system containing Mesalazine is an aminosalicylate drug used to treat mild to moderate active ulcerative colitis and also to maintain remission once achieved. The basic design consists of an insoluble hard gelatin capsule body, filled with powder blend and sealed with a hydrogel plug. The powder blend containing Mesalazine, Crospovidone, Lycoat, SSG, MCC and talc was prepared and evaluated for flow properties and FTIR studies. From the obtained results, F8 powder blend formulation was selected for further fabrication of pulsatile capsules. Hydrogel plug was formulated in a lone and in combination of hydrophobic polymer like ethyl cellulose with hydrophilic polymers like HPMC K15M as a ratio of Ethyl cellulose: HPMC K15M in 1:1, 1:2, and 2:1 ratio to maintain a suitable lag period and it was found that the drug release was controlled by the proportion of polymers used. The prepared formulations were evaluated for drug content, weight variation and Invitro release studies. FTIR studies confirmed that there was no interaction between drug and polymers and Invitro release studies of pulsatile device revealed that increasing hydrophilic polymer content resulted in delayed release of Mesalazine from the pulsincap after a predetermined lag time of 6hrs. Based on invitro studies performed, C3F8 was found to be optimized formulation.