Fig. 1.

A graphical representation of the Systems Approach to drug delivery and targeting. The Systems Approach is based on integration of the intercepts among four areas of biomedical knowledge: (1) drug target localization information from an intracellular context to cells and tissues as well as organs in the body, (2) knowledge about the biodistribution and clearance of drug candidates in the body over time, (3) the physiological and pathological consequences of the aberration in drug targets that reflect disease symptoms, and (4) quantitative or bioanalytical markers that could be measured in blood or other samples for predicting drug levels and disease outcome. These overlapping themes and conditions should be taken into consideration when implementing the Systems Approach to drug delivery and targeting