||spherical particles that consist of a myriad of inter connecting voids within non-collapsible structures with a large porous surface. Microsponges containing Ethyl cellulose and Eudragit RS 100 were prepared by Quasi-emulsion solvent diffusion method using Etodolac as a model drug. The effects of different drug to polymer ratios on physical characteristics of the microsponges were investigated. Thermal behavior, surface morphology, particle size and pore structure of the microsponges were examined. In-vitro drug release rate from the microsponges was also investigated. In-vitro dissolution study showed that the release rate of the dug has been modified. This study presents a new approach based on microsponges for colon specific drug delivery.