FORMULATION APPROACHES FOR SUSTAINED RELEASE DOSAGE FORMS: A REVIEW

Over the past 30 years, as the expense and complications involved in marketing new drug entities have increased, with concomitant recognition ofthe therapeutic advantages of controlled drug delivery, greater attention has been focused on development of sustained or controlled release drugdelivery systems (DDS). For many disease states, a substantial number of therapeutically effective compounds already exist. The effectiveness of thesedrugs is often limited by side effects or necessity to administer the compound in an ethical setting. The goal in designing sustained drug deliveryis to reduce the frequency of dosing or to increase the effectiveness of the drug by localization at the site of action, reducing the dose required orproviding uniform drug delivery. The design of oral sustained release DDS depends on various factors such as, physicochemical properties of drug,type of delivery system, disease being treated, and patient condition, and treatment duration, presence of food, gastrointestinal motility, and coadministrationof other drugs.Keywords: Sustained release drug delivery system, Dose frequency, Biological half-life, Physicochemical properties of drugs