Abstract

SUSTAINED RELEASE MATRIX TYPE DRUG DELIVERY SYSTEM: A REVIEW

Vinay Kumar*, S K Prajapati, Girish C Soni, Mahendra Singh, Neerajkumar

Institute of Pharmacy, Bundelkhand University, Jhansi-284128. U.P. India.

ABSTRACT

In recent years scientific and technological advancements have been made in the research and development of oral drug delivery system. The reasons that the oral route achieved such popularitpy may be in part attributed to its ease of administration. Presently pharmaceutical industries are focusing on development of sustained release formulations due to its inherent boons. Sustained release dosage forms are designed to release a drug at a predetermined rate by maintaining a constant drug level for a specific period of time with minimum side effects. Hydrophilic gel-forming matrix systems are widely used in oral controlled-release dosage forms. Hydrophilic polymer hydrates form a viscous gel layer around the tablet surface, and drug release is controlled in a sustained manner by diffusion through a gel layer and the erosion of the gel. Drug solubility, however, greatly affects the rate of diffusion and erosion. It is especially difficult to control the release rate of highly water-soluble and insoluble drugs. Moreover, various gastrointestinal factors such as ionic strength and mechanical destructive force also affect the drug-release rate. To solve these problems or predict these influences, many studies have examined factors affecting drug release. Sustained release products are designed to bring the blood level of a drug immediately to therapeutic concentrations by means of an initial dose portion called loading dose and then sustain this level for a certain predetermined time with the maintenance portion. The basic goal of sustained release is provide promising way to decrease the side effect of drug by preventing the fluctuation of the therapeutic concentration of the drug in the body and increase patient compliance by reducing frequency of dose.

Keywords: sustained release, Oral controlled release drug delivery system, Hydrophilic Matrix system. Patient compliance.