Content area
Full Text
ABSTRACT:
The new generation of oral controlled release drug delivery system technologies brings valuable benefits to patients. Oral route is the most convenient and commonly route of drug delivery. Oral controlled release formulations are designed to deliver a drug at a pre determined rate by achieving a constant drug level for a specified period of time with lower side effects. Controlled release drug delivery have become a significant priority worldwide, it may be possible to achieve rapid absorption of drug and increased bio availability, reduced toxicity and improved patient compliance. This article mainly focuses the requirement of controlled drug delivery system, their advantages, disadvantages, formulation, various methods and use of controlled release system.
KEYWORDS: Controlled release drug delivery system, prolonged release, Zero-order, Half life Diffusion controlled.
(ProQuest: ... denotes formulae omitted.)
INTRODUCTION:
Over the past 30 years, as the expense and complications involved in marketing new drug entities have increased, with concomitant recognition of the therapeutic advantages of controlled drug delivery, greater attention has been focused on development of sustained or controlled release drug delivery systems. There are several reasons for the attractiveness of these dosage forms. It is generally recognized that for many disease states, a substantial number of therapeutically effective compounds already exist1. The effectiveness of these drugs, however, is often limited by side effects or the necessity to administer the compound in a clinical setting. The goal in designing sustained or controlled delivery systems is to reduce the frequency of dosing or to increase effectiveness of the drug by localization at the site of action, reducing the dose required, or providing uniform drug delivery.
TERMINOLOGY:
In general, the goal of a sustained release dosage form is to maintain therapeutic blood or tissue levels of the drug for an extended period. This is usually accomplished by attempting to obtain zero order release from the dosage form. Zero order release constitutes drug release from the dosage form that is independent of the amount of drug in the delivery system (i.e., a constant release rate). Sustained release systems generally do not attain this type of release and usually try to mimic zero order release by providing drug in a slow first order fashion (i.e., concentration dependent)2. Systems that are designated as prolonged release can...