An official generic and non-proprietary name provided to a pharmaceutical medicine or active ingredient is called an international non-proprietary name (INN). To reduce prescribing errors, INNs are designed to make communication more accurate by providing a unique standard term for each active ingredient. Since 1953, the World Health Organization (WHO) has coordinated the INN system. INN structures are publicly available and can be used to study drug research and development trends, however they are underutilised. We looked at how a common drug name is made up and analysed chemical entities in this chapter.