Virtual Drug Development

In addition to drug design, computers are used for modelling human disease and response to therapy. Research and drug development can be carried out in a virtual laboratory using computer-based models of human disease, target validation and patient selection for clinical trials. Drug testers turn to ‘virtual patients’ as guinea pigs and this technology can reveal unseen biological interactions that explain conflicting clinical trial results.
Virtual screening is a strategy for introducing a more focused approach to HTS. Computational analysis of very large real or virtual chemical databases can readily identify compounds with appropriate properties for binding to the target receptor. Full receptor–ligand docking represents the most detailed – and the most time-consuming –approach to virtual screening. One of the aims of introducing computational methods in the drug discovery process is the early elimination of compounds which are chemically unsuitable for further development.
This approach is needed because HTS is identifying a large number of hit compounds, many of which do not possess drug-like properties. Several methods for predicting drug likeness have been described but the focus is on the prediction of intestinal absorption and blood–brain barrier penetration. The routine use of experimental absorption systems in the pre-screening of compounds has provided data that can be used for construction of improved models of drug absorption. Use of such systems have the potential to reduce lead optimisation time and attrition rates in preclinical and clinical phases of drug development.