Graphic: Cathleen Heard

Because most drugs undergo development and approval for seven to 10 years before coming to market, researchers are always looking for ways to speed the process. Preclinical drug testing involves both in vitro and animal assays that assess efficacy and potential side effects to predict how the agent will affect humans. Drug toxicity can result in such things as cancer and birth defects, so government agencies have set forth strict guidelines for toxicological testing. In part because it is highly proscribed, toxicology has been slow to incorporate innovations. However, its almost ritualistic approaches are beginning to change, and cutting-edge technologies are being applied. This is good news for patients and pharmaceutical companies, who can expect more rapid drug discovery and safer drugs.

In Vitro Toxicological Models

A drug can be toxic at different levels, but drug-induced mutagenesis of DNA underlies many adverse effects. Genotoxicity tests measure a...