ABSTRACT:
The objective of this study was 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 Diclofenac sodium 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 diclofenac microcapsules were prepared in four batches, with Eudragit RS-100 by varying drug to polymer ratio and evaluated for the particle size, drug content and in vitro release profile and from the obtained results; one better formulation was selected for further fabrication of Pulsatile capsule. Different grades of HPMC hydrogel polymer were used as plugs, to maintain a suitable lag period and it was found that the drug release was controlled by the proportion of polymers used. The entire capsule was enteric coated by using eudragit L-100, so that colon specific release can be achieved. 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 diclofenac sodium from microcapsule.