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This glossary gives definitions for the main regulatory terms used on this website and in European Medicines Agency (EMA) documents.

Click on a letter below to see terms beginning with that letter.

Disclaimer: EMA has developed the definitions in this glossary to help this website's users understand regulatory terminology. Definitions may differ from those given in European Union legislation.



The extent to which an active ingredient is absorbed from a medicine and becomes available in the body.


When two medicines release the same active ingredient into the body at the same rate and to the same extent under similar conditions.

biological medicine

A medicine whose active substance is made by a living organism.


A biological molecule found in blood, other body fluids, or tissues that can be used to follow body processes and diseases in humans and animals.

For more information, see biomarkers.

biomarker qualification

Certification of the acceptability of a biomarker for a specific use in pharmaceutical research and development. The Agency gives opinions on biomarker qualifications.

For more information, see qualification of novel methodologies for medicine development.

biosimilar medicine

A medicine that is similar to a biological medicine that has already been authorised.

For more information, see biosimilar medicines.


The use of living organisms to create or modify products, including medicines.