Targeted drug delivery

Creating effective targeted drug delivery strategies is an integral compone nt of the overall process of drug development. The four key requirements of an effective drug delivery system are retain, evade, target and release. I ncreasing the therapeutic index (TI) of a delivered compound by selectively delivering it to target areas is a goal that has many obstacles. Some of t hese concerns have been addressed by recent developments in areas such as l iposomes, prodrugs, external targeting, controlled gene expression and anti bodies. An analysis of some of the relevant inventions is discussed below. In order to present these inventions in a new light, materials science and engineering approaches have been used to examine the patents and help discu ss their advantages and disadvantages. Patents concerning the manipulation of genes and proteins are at the core of this research and are an integral part of its future. Very specific targeting is possible when working at thi s level. The most exciting developments combine targeting strategies for de livery systems with many layers of specificity, increasing their targeting potential. It is also important to understand (and possibly exploit) the ar ea to which a delivery system is being targeted and to learn from nature's own delivery systems. Examples of these systems, including the red blood ce ll, the neutrophil and the secretory granule, are discussed using a materia ls engineering approach. This analysis reveals numerous characteristics tha t nature has designed into its delivery systems, and how these are importan t when creating man-made products. Working with these kinds of ideas, a tru e 'magic bullet' may be discovered.