Drugs usually act on soluble, cellular or microbial proteins, known as drug targets, which are believed to be associated with a disease. Scientists use a variety of molecular, genetic or pharmacological techniques to identify a target and learn more about how it influences the disease.

To select targets most likely to be useful for the treatment of a disease, researchers compare each drug target to others based on their association with a specific disease and their ability to regulate biological processes in the body. Tests confirm that interactions with the drug target are the desired change in the behaviour of the diseased cells.

Laboratory assays are developed that allow a rapid screening of small molecules or proteins. In these tests, a compound that specifically binds to the desired target is selected. Leads are sometimes developed from collections of larger chemical libraries or smaller sets of molecules that possess drug-like properties.

Lead optimisation aims to improve properties of the identified leads to support the selection of those compounds with the greatest potential to be developed into safe and effective medicines. The best lead compounds are studied for their therapeutic effects and how they are absorbed, metabolised and excreted in animals.

During the preclinical development of a drug, laboratory tests document the effect of the investigational drug in living organisms (in vivo) and in cells in the test tube (in vitro) to ensure it will be safe. Testing must also provide information about how the drug will be best formulated and manufactured, and how it would be best administered to patients.

Clinical trials, normally performed in healthy volunteers to investigate absorption, distribution in the human body and excretion of an investigational compound and to establish short term tolerability and safety for a preliminary dose range. Boehringer Ingelheim has two Human Pharmacological Centers in operation in Germany (Ingelheim and Biberach).

Efficacy and safety in the target indication is established with up to several hundred patients treated for usually several weeks or few months. The final dose range is determined, which will be investigated further in phase III.

Phase II results on efficacy and safety are refined and confirmed in larger patient numbers (several thousands) and long term treatment as appropriate for the indication.

After clinical studies, results are submitted to regulatory agencies. Independent experts give their opinion on whether or not the drug product should be approved.

The product is further profiled for more general and broader real-life usage, in special patient subgroups and in the context of an even broader concomitant therapeutic environment. These trials may be extremely large (10 - 30,000 patients) and therefore can better identify even rare adverse reactions.