Osmotically regulated asymmetric capsular system for sustained delivery of indomethacin

The aim of the current study was to develop a sustained release asymmetric membrane capsular system for oral delivery of indomethacin. The capsule membrane was prepared using fabricated glass mold pins by phase inversion technique. Cellulose acetate was used as the semi permeable membrane. The capsule contains pore-forming water-soluble additives, which after coming in contact with aqueous medium, dissolves, resulting in an in situ formation of a micro porous structure. The effect of different formulation variables, like, ratio of drug to osmogen, solubilizing agent and level of pore former, stirring rate on the in vitro release was studied. Scanning electron microscopy of the membrane confirmed its porous, dense asymmetric nature. It was found that drug release rate increased with the increase in amount of osmogen and solubilizer, and independent of stirring rate. Indomethacin release was, directly proportional to the level of pore former, in the membrane. In the present investigation, efforts have been made to increase the release of poorly water soluble drug by means of porosity osmotic pump.