In the present work an attempt has been made to develop and evaluate a time or site specific pulsatile drug delivery system. The basic design consists of an insoluble hard gelatin capsule body, filled with Eudragit microcapsules of Losartan potassium and sealed with a hydrogel plug. The entire capsule was enteric coated, so that the variability in gastric emptying time can be overcome and a colon-specific release can be achieved. The Losartan potassium microcapsules were prepared by solvent evaporation method with Eudragit L-100 and S-100 (1:2) by varying drug to polymer ratio and evaluated for the particle size, angle of repose, percentage yield, drug content, SEM, IR and invitro release study. Most of the isolated microcapsules were of particle size range 135 to 655mm, the angle of repose was in the range of 23o 95” to 30o 40”. Bulk and tapped densities showed good packability and Carr’s index ranges from 15.71 to 19.11. The drug loaded microcapsules show 68.93 ± 0.37 to 80.12 ± 0.62 drug entrapment. The in-vitro, drug release studies were carried out using pH 6.8 phosphate buffer for 12 hrs. At the end of 12thhrs the drug release in the range of 84.96± 1.53 to 98.45 ± 0.24 and from the obtained results; one of better formulation was selected for further fabrication of Pulsatile capsule. Different grade of HPMC hydrogel polymer were used as plugs in different ratios, to maintain a suitable lag period and it was found that the drug release was controlled. The entire capsule was enteric coated with 5% CAP, so that colon specific release can be achieved. The formulated pulsatile device was evaluated weight variation, thickness of CAP, IR, and in-vitro release study. The in-vitro release studies of pulsincap system revealed that colon specific release has been achieved, increasing the hydrophilic polymer content resulted in delayed release of losartan potassium from microcapsule.