Putting pills to the test

In the search for new agents, drugs manufacturers today spend about twice as much as they did just ten years ago. But this has not resulted in many more drugs being approved each year. Often the candidate agents fail the expensive clinical studies. In order to avoid such failures, companies are trying in advance to select the most promising candidates from the enormous number of possible agents. But how can they be found? Of course, it's not possible to experimentally check up to 1024 various molecules (that is billions times billions of molecules). "But it can be done with the help of computers," says Dr. Igor Tetko from the GSF - National Research Center for Environment and Health in Munich. The bioinformatician develops programmes that simulate the specific chemical and biological properties of a molecule on the basis of its descriptors. With the help of these models it is possible to predict whether a substance is absorbed and distributed by the body and whether it is possibly toxic. This can spare drugs manufacturers from unpleasant surprises when testing new drugs and agents in clinics.