Drug delivery systems: A brief review

Abstract

Two basic approaches to drug delivery were described. For controlled release systems, the goal is to achieve temporal control over drug levels in [human] body compartments such as the plasma and have proceeded mainly from an engineering and material science viewpoint. The technology for controlled release systems is quite highly developed and several clinically useful products have been produced. The 2nd type of system, the goal is both temporal and spatial control of pharmacokinetic parameters. Developments in this area have proceeded from a biological and biochemical framework, and have relied and will continue to rely on knowledge of the structure and function of cell membranes. Few significant clinical applications of liposomes or of other systems for controlled drug disposition have appeared, but the potential advantages conferred by highly discriminating control of drug kinetics and distribution are very great and certainly warrant a careful exploration of the capacities of systems of this sort. A potential problem for all drug delivery technologies is one of economics. The use of delivery systems may be limited to situations where the attainment of adequate drug levels in a target tissue is of critical importance for the preservation of life and of normal physiological functions.