ABSTRACT
As a result of rational drug design or the employment of combinatorial chemistry in combination with high throughput screening, a huge number of novel active molecules emerges. However, many such potential leads exhibiting high affinities towards a variety of molecular targets (i.e. receptors, enzymes, etc.) are, per se, prevented from becoming real drug candidates due to their inherent physicochemical properties. This being based on the fact that only seldomly an active agent with optimal structural configuration for eliciting the desired therapeutic response at the target site possesses the best molecular form and properties for its delivery to the site of ultimate action (see Section 14.1.2).
