Microsponge Based Colonic Drug Delivery Systems

This study encompasses preparation microsponges based colon specific tablet formulations. Initially, microsponges of dicyclomine and paracetamol were prepared by quasi-emulsion solvent diffusion method. The reason for preparing microsponge due to the fact that, drug carrier systems less than 200 ¿m may efficiently be taken up by the macrophages present in colon tissue, thus exhibit effective localized drug action at the desired site. A subsequent increase of residence time that may be postulated for microsponges as compared to existing drug delivery systems may allow dose reduction and enhance therapeutic effect. Another reason for preparing microsponges was their sponge like texture that can easily be compressed by direct compression for producing mechanically strong tablets. Then core tablets of microsponges were prepared by direct compression method and were compression coated with pectin:HPMC mixture. The reason for selecting pectin was its biodegradation in the colon by colonic flora. HPMC is reported to increase the mechanical strength of the tablet coat and helped in maintaining its integrity during its sojourn in the gastro-intestinal tract.