SUSTAINED RELEASE DRUG DELIVERY SYSTEM: AN OVERVIEW

Abstract

Among various drug delivery systems, oral drug delivery is the most preferred route for administering drugs. Sustained release products offer advantages over conventional dosage forms by optimizing the biopharmaceutical and pharmacokinetic properties of drugs. Sustained release formulations help reduce drug side effects by preventing fluctuations in the therapeutic concentration within the body. The availability of various polymers and extended dosing intervals supports the development of sustained release products. These formulations come in various forms, such as extended release, targeted release, delayed release, and prolonged action dosage forms. Factors like molecular size, diffusivity, pKa-ionization constant, release rate, dosage, stability, duration of action, absorption window, therapeutic index, protein binding, and metabolism influence the design of sustained release formulations. These formulations are evaluated based on criteria like weight variation, friability, hardness, thickness, and in vitro release rate. The future of sustained release products is promising, especially in areas such as chrono-pharmacokinetic systems, targeted drug delivery systems, mucoadhesive systems, and particulate systems that provide high promise and acceptability. This article discusses various types, evaluations, and factors affecting sustained release formulation design.