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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 use of tiny structures less than 1,000 nanometres across, which are designed to have specific properties.

For more information, see nanotechnology.

national competent authority

A medicines regulatory authority in a European Union Member State.

nationally authorised product

A medicine authorised in a Member State in accordance with its national authorisation procedure.

note for guidance

A type of document intended to provide guidance on an aspect of a regulatory procedure.