ABSTRACT
In the past, drug candidates were first optimized for potency (binding affinity, selectivity). Absorption, distribution, metabolism, and excretion (ADME) were usually considered at a later stage. In this scenario, when development was hindered by
Introduction ............................................................................................................303 Physicochemical Parameters Governing Drug Absorption ...................................304 Approaches to Solubility ........................................................................................305 Solubility Classes: High-Medium-Low ................................................................306 Approaches to Permeability ...................................................................................306 Case Studies ...........................................................................................................307 Conclusion and Outlook ......................................................................................... 310 References .............................................................................................................. 311
ADME issues, the only rescue option available was to enter an extensive formulation program to minimize factors that prevent absorption. This approach is, however, always expensive and not always successful. In addition, it basically only applies to the absorption part, with distribution, metabolism, and excretion being closely associated with the intrinsic properties of the active ingredient.
