An ideal drug delivery system should deliver precise amounts of a drug at a preprogrammed rate to achieve a drug level necessary for treatment of the disease. For most drugs that show a clear relationship between concentration and response, the drug concentration will be maintained within the therapeutic range, when the drug is released by zero-order rate. In order to design a controlled release delivery system, many factors such as physicochemical properties of the drug, route of drug administration, and pharmacological & biological effects, pharmaceutical excipients used etc. These...