Guidelines on the Use of International Nonproprietary Names (INNs) for Pharmaceutical Substances
(1997; 41 pages) View the PDF document
Table of Contents
Open this folder and view contents1. General introduction
Close this folder2. Elements in the INN system
View the document2.1 Proposed INNs
View the document2.2 Recommended INNs
View the document2.3 Names for radicals and groups
View the document2.4 Modified INNs (INNMs)
View the document2.5 Cumulative list of INNs
Open this folder and view contents3. Principles for selection of INNs
View the document4. Protection of INNs
Open this folder and view contents5. How to apply for an INN
View the document6. References for supporting material
View the documentAnnex 1: Background information on the INN programme
View the documentAnnex 2: General principles for guidance in devising international nonproprietary names for pharmaceutical substances
View the documentAnnex 3: List of common stems used in the selection of INNs
View the documentAnnex 4: Specific groups of biological compounds
View the documentAnnex 5: WHA46.19 - Nonproprietary names for pharmaceutical substances
View the documentAnnex 6: Procedure for the selection of international nonproprietary names for pharmaceutical substances
View the documentAnnex 7: Applications for INNs through national authorities (addresses)
View the documentAnnex 8: INN request form

2.1 Proposed INNs

The selection of a new INN relies on a strict procedure. Upon receipt of an INN request form, the WHO Secretariat examines the suggested names for conformity with the general rules, for similarities with published INNs and potential conflicts with existing names, including published INNs and trademarks. A note summarizing the result of these checks is added and the request is subsequently forwarded to the INN experts for comments. Once all experts agree upon one name, the applicant is informed of the selected name.

Newly selected, proposed INNs are then published in WHO Drug Information, which indicates a deadline for a 4-month objection period. This period is allowed for comments and/or objections to the published names to be raised. The reasons for any objection must be stated clearly and these will be evaluated by the experts for further action. Users are invited to refrain from using the proposed name until it becomes a recommended INN, in order to avoid confusion should the name be modified. Two lists of proposed INNs are published yearly. An example is set out below.

acidum iocanlidicum (123I)


iocanlidic (123I) acid

15-(p-[123I]iodophenyl)pentadecanoic acid
radiodiagnostic agent

acide iocanlidique (123I)

acide 15-(p-[123I]iodophényl)pentadécanoïque
produit a usage radiodiagnostique

ácido iocanlídico (123I)

ácido 15-(p-[123I]iodofenil)pentadecanoico
agente de radiodiagnóstico





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