In the Harmonized System, International Nonproprietary Names (INN) for pharmaceutical substances could be frequently seen especially in Chapter 29. Developed by the World Health Organization (WHO) since the 1950s, these names can be recognized and used globally by doctors, pharmacists, scientists, medicines regulators and patients.

Each INN must be unique, distinctive in sound and spelling. It must not be liable to confusion with other names in common use, in particular trade names for medications or with diseases that it may have been developed to treat. It belongs to everyone and yet no one owns it. It is similar to its other close relations but is distinctly different from the other 9500 that came before it.

INNs usually contain a common syllable (known as a stem) to indicate the pharmacological or chemical family to which the substance belongs. The ending –mycin, for example – denotes a type of antibiotic. Syllables, letters or separate words are then added to differentiate between substances in the same family – such as kanamycin, etc.

New INNs must be accepted and easily used by many different languages and cultures. There are currently around 4000 INNs in active use worldwide. The list grows by 160–230 new INNs each year as new pharmaceutical substances request an INN.

Twice a year, the INN Expert Group gathers at the WHO to painstakingly consider and create names for new substances used in medicines. At the WCO, the Scientific Sub-Committee and the Harmonized System Committee work together to classify all of these products to help simplify trade.

By assigning a single international name to drugs, the WHO helps ensure that a prescription filled abroad is what the doctor ordered back home.

(graphic from WHO)