The aim of the study was to develop and evaluate enteric coated matrix tablet of Aceclofenac for colonic delivery by exploiting prolonged release characteristics of HPMC K4M with pH dependent solubility property of a Eudragit S100. Extended release matrix tablet were prepared by direct compression of hydrophilic polymer HPMC and other ingredients. The pH dependent release was achieved by coating matrix tablet with Eudragit S100, soluble at pH 7. All the formulations of 32 factorial design (A1- A9) were evaluated for the physicochemical parameters and subjected to in vitro drug release in 0.1...