Pharmaceutical products, more often than not, contain non medicinal substances known as excipients. They are intended to enhance manufacturing process, make dosage formulation acceptable, bulking up solid formulations that contain potent active ingredients in small amounts and to confer a therapeutic enhancement on the active ingredient in the final dosage form However, their quality and quantity in a formulation may influence release properties of the active drug: As a result, dosage formulation of the same drug by different manufacturers in the same country or different countries might also exhibit a variety of drug release characteristics and this often can affect bio-availability and ultimately clinical effectiveness. Hence, this article review endeavors to appraise the effect of formulation excipients on drug release characteristics of extended release tablets.