Overview
This lecture covers the World Health Organization’s (WHO) system for International Nonproprietary Names Modified (INNM), explaining how to systematically name pharmaceutical substances—especially variants like salts, esters, hydrates, and polymeric forms—based on established INNs.
INNM Programme Purpose and Principles
- WHO established the INN Programme to standardize naming for pharmaceutical substances to aid clear communication among health professionals.
- INNMs are modified versions of INNs used to name derivatives (salts, esters, etc.) of active pharmaceutical ingredients.
- INNMs add chemical information to substance names for better clarity and safety in prescribing and dispensing.
- Abbreviated names for complex radicals and groups are available to simplify names.
Naming Salts of Basic Compounds
- For a base, create a salt name by adding the acidic part (from the acid) as a second word.
- Latin names use the genitive for the base and nominative for the acid; English uses the unchanged INN followed by the anion.
- Suffixes for the acid part: Latin -oicum/-icum to -oas/-as; English -oic/-ic to -oate/-ate.
Naming Salts of Acidic Compounds
- Acidic compounds often have groups like -COOH, -SO₃H, or -PO₃H₂.
- Salts are named by combining the acid component with the cation, sequence and forms vary by language and compound structure.
- Some one-word acid INNs remain unchanged in INNMs.
Hydrates and Other Solvates
- Hydrates are named by adding “hydrate” to the INN, with prefixes for number of water molecules if needed.
- Hydrates of salts are indicated after the salt name.
Esters (Acid and Alcohol Functions)
- Esters are named with a two-word structure: one for the acid and one for the alcohol-derived radical.
- Modifications to suffixes in Latin/English depend on whether the INN is two words or one word.
- For alcohol-based INN esters, the alcohol name is unchanged in English, modified in Latin.
Quaternary Substances
- Quaternary salts are named with the cation and anion as separate components.
- Latin uses the genitive for the cation; English keeps the base name unchanged.
Combination Products and Complexes
- INNMs for combinations or complexes are created by simply listing the INNs of the components together.
- If a component lacks an INN, its established chemical name is used.
Polymeric Series Members
- Families of polymers are named with the INN plus a numerical designator indicating average molecular mass.
- Monoesters of such polymers follow the same format with an added fatty acid name.
Improper Use of INNM Approach
- The INNM approach should not be used to create unauthorized or composite names.
- Special rules exist for complex substances—like polypeptides—using additional designators through the standard INN process.
Key Terms & Definitions
- INN (International Nonproprietary Name) — a unique, globally recognized name for a pharmaceutical substance.
- INNM (International Nonproprietary Name Modified) — a systematically constructed name for a derivative or variant of an INN.
- Salt — a compound formed from an acid and a base.
- Ester — a compound formed from an acid and an alcohol.
- Hydrate — a compound containing water molecules.
- Quaternary Substance — a compound with a quaternary ammonium or other positively charged center.
- Polymeric Series — a family of polymers differentiated by numerical designators.
Action Items / Next Steps
- Review the "General principles for guidance in devising INNs" for deeper understanding.
- Refer to the WHO document WHO/EDM/QSM/2004.6 for a list of abbreviated group names.
- Practice constructing INNMs for various derivatives using the outlined rules.