A Review on-Controlled-Porosity Osmotic Pump Tablet

Conventional oral drug delivery systems supply continues release of drug, which cannot release of the drug and effective concentration at the target site. Drug can be delivered in a controlled manner over a long period of time by the process of osmosis. Osmotic devices are the most promising technique for controlled drug delivery. Osmotic drug delivery system is one among the controlled drug delivery employed orally and also as an implantable devices. Various patents available for osmotic drug delivery system like Rose-Nelson pump, Higuchi leeper pump, Higuchi Theeuwes pump, Elementary Osmotic pump etc. various techniques available for preparation of Osmotic Drug Delivery System include Push pull osmotic pump, Osmotic bursting osmotic pump, Liquid oral osmotic system, Sandwiched osmotic tablets, monolithic osmotic system and Controlled porosity osmotic pump. The present review is concerned with the study of drug release system which are tablets coated with walls of controlled porosity. When these system are exposed to water, low levels of water soluble additives is leached from polymeric material i.e. semi permeable membrane and drug releases in a controlled manner over an extended period of time. Drug delivery from this system is not influenced by the different physiological factors within the gut lumen and the release characteristics can be predicted easily from the known properties of the drug and the dosage form. In this paper, various type of osmotically controlled drug delivery systems and mainly the basic components and evaluation parameter of controlled porosity osmotic pump tablets have been discussed briefly.