Using in vitro human tissues to predict pharmacokinetic properties.

: Pressure on drug discovery teams to predict the success of drug candidates earlier in the drug discovery process has led to the development of in vitro assays using human tissues, cells or fluids that aid chemists and biologists in their decision-making process. The use of human material is often related to the species-specific nature of the enzymatic biotransformations or transport processes that are involved in drug bioavailability. In vitro assays have been developed to indicate liabilities in scaffolds relating to the absorption, distribution or metabolism of new chemical entities. These models have been applied not only to screening and ranking of potential drug candidates but also to the understanding of the mechanisms leading to in vivo pharmacokinetic outcomes. The use of these models is leading to the development of structure-ADME property relationships in a manner similar to classical structure-activity relationship development, and in the future this is expected to lead to in silico models for predicting physiological and pharmacological effects prior to experimentation.