Out of every 5,000 new compounds identified during the discovery process only five are considered safe for testing in human volunteers after preclinical evaluations. After 3 to 6 years of further clinical testing in patients, only one of these compounds is ultimately approved as a marketed drug for treatment. Scientists use a variety of techniques to identify and isolate a target and learn more about its functions and how these influence disease. Compounds are then identified, which have various interactions with drug targets that are helpful in treatment of a specific disease. Tests are conducted to confirm that interactions with the drug target are associated with a desired change in the behavior of diseased cells.
Research scientists can then identify compounds that have an effect on the target selected.
Lead identification . A lead compound or substance is one that is believed to have potential to treat disease. Laboratory scientists can compare known substances with new compounds to determine their likelihood of success. Testing is then done on each of these molecules to confirm its effect on the drug target. Lead optimization .