Naming of excipients: future challenges

16. November 2015

Paper prepared for the <INN Expert Group discussion by Professor Witold Wieniawski, Polish Pharmacopoeia Commission, Warsaw and Dr Wai Keung Chui, Department of Pharmacy, National University of Singapore.

Activities of the INN Programme have focused on selecting names for active pharmaceutical substances used in human and veterinary medicine while expanding only incidentally to other types of substances and products used directly or indirectly for health purposes. The rules governing the allocation of INNs are specifically adapted to indicate the therapeutic activity of a single substance and these rules may not be appropriate for naming of other types of products. However, over the years, the success of the Programme has led to requests for expansion into other areas, especially in cases where divergence in naming practices creates difficulties for international cooperation. One possible area highlighted for expansion is the naming of excipients.

At present, the naming of excipients is carried out with regard to chemical composition. Existing approaches to
assigning names may include trivial (traditional) names, systematic chemical (IUPAC) names, or International
Nonproprietary Names (INNs). Options available for the selection of excipient names include one-word names with
syllables indicating specific properties of the substance, or an alphanumeric system.

The International Pharmaceutical Excipients Council (IPEC) has defined pharmaceutical excipients as any
substance, other than the pharmacologically active ingredient, that has been appropriately evaluated for safety and
is included in a drug delivery system to:

(i) facilitate the process of manufacturing of the medicinal product;
(ii) protect, support or enhance the stability and bioavailability of the active ingredient;
(iii) aid in the identification of the finished product;
(iv) enhance any other attribute of the overall safety and efficacy of the medicinal product during storage or use.

The INN Programme has already named those pharmaceutical substances that may serve a dual purpose as
excipients or as pharmacologically active ingredients. INNs have also been assigned to a few specific groups of
polymeric excipients such as cellulose derivatives, macrogols, macrogol esters, sorbitan esters, macrogol-sorbitanfatty acid polymers, polysiloxanes, and poloxamers