Asymmetric Membrane Capsule (amc): an Useful Osmotic Drug Delivery System

Osmotic drug delivery mechanism is well known in the field of oral controlled release systems. The release of drug from the osmotic drug delivery devices is based on the phenomenon of osmosis. An useful technology developed for osmotic delivery of drug is asymmetric membrane capsule (AMC), which is an economic and effective drug delivery device as compared to other existing technique of osmotic drug delivery like osmotic tablets. It can be prepared by a simple process known as Phase Inversion. Osmotic delivery system show less bioavailability fluctuation as compared to oral conventional controlled release (CR) systems because it releases drug independent of gastrointestinal (GI) physiological factors. Asymmetric membrane is prepared by using water insoluble polymer like ethyl cellulose (EC), cellulose acetate (CA), cellulose acetate butyrate (CAB). In this system role of osmogen is important to release the drug from it. Both water soluble or insoluble drugs can be delivered using AMC. Various categories of drug that can be formulated in AMC are NSAIDS, cardiovascular drugs, anti-diabetic drugs, antibiotics etc. This article presents an overview of AMC as an effective dosage form for oral osmotic controlled drug delivery of various categories of drugs.