26A REVIEW ON ORAL CONTROLLED DRUG DELIVERYThe process or method of administering a pharmaceutical compound for the purpose to create a therapeutic effect for animals and humans is known as drug delivery. A drug delivery technology is a patented form of technology, which modifies the absorption, drug release profile, elimination and distribution for the sake of enhancing the safety and efficacy of the p roduct to provide compliance and convenience to the patients. In recent years a wide variety of newer oral drug delivery system like sustained/ controlled release dosage forms are designed and evaluated in order to overcome the limitation of conventional therapy. These products are able to maintain steady drug pl asma levels for extended periods of time as a result the variation of the drug levels in the blood are prevented and minimized drug related side effects. This review mainly focused on oral drug delivery system of drugsrikanthp.06@gmail.com Review312013Controlled drug delivery,Diffusion controlled drug release,Dissolution controlled drug releaseP. Srikanth,Narayana Raju,S. Wasim Raja,S. Brito RajDepartment of Pharmaceutics, Sri Venkateswara College of Pharmacy, R.V.S. Nagar, Tirupati Road, Chittoor, Andhra Pradesh,Department of Pharmaceutics, Sri Venkateswara College of Pharmacy, R.V.S. Nagar, Tirupati Road, Chittoor, Andhra Pradesh,Department of Pharmacy Practice, Sri Venkateswara College of Pharmacy, R.V.S. Nagar, Tirupati Road, Chittoor, Andhra Pradesh,Department of Pharmaceutics, Sri Venkateswara College of Pharmacy, R.V.S. Nagar, Tirupati Road, Chittoor, Andhra Pradesh