The applications of parallel synthesis and combinatory chemistry to expedite lead finding and lead optimization processes have shifted the chemical libraries toward poorer biopharmaceutical, ADME (absorption, distribution, metabolism, and excretion), and pharmacokinetic (PK) properties. A drug candidate should have desirable biopharmaceutical properties such as good solubility and good permeability, as well as optimal and ADME/PK properties. The early knowledge of liability of biopharmaceutical, ADME/PK, and DDI properties is very valuable in drug candidate selection process. In the last one decade, multiple
in silico, in vitro,
and
in vivo
ADME studies have been developed and implemented in the drug discovery and development process to alert chemists and drug metabolism scientists of the potential ADME, PK and DDI issues in the clinic. In this chapter, we attempt to discuss these various ADME profiling approaches in drug discovery and development process and the latest technologies of the selected assays.