Targeting Using Physical Approaches and Particulate Drug Carriers: Interaction with the Biological Milieu

Abstract

In many disease conditions, selectivity in drug delivery would be of considerable advantage. Cancer chemotherapy is the often quoted example where antitumor drugs can destroy the target (tumor cells) but can also have an undesirable effect on non-target cells. This chapter will focus on the possibilities and pitfalls of attempting drug targeting using physical approaches such as colloidal particles in the form of microspheres, liposomes or emulsions. Firstly, the feasibility of targeting needs to be considered. In some attempts at so called ‘Drug targeting’, it can be overlooked that the target may not be well defined. Certainly it is important to decide at a very early stage what one is aiming at, and whether the target is discrete and accessible. In addition, some differences between target and non-target must be discernible.