Drug system identifiers (manufacturer-specific including inactive ingredients):
Hierarchical systems:
Ingredients:
Proprietary database identifiers include those assigned by First Databank, Micromedex, MediSpan, Gold Standard Drug Database (published by Elsevier), and Cerner Multum MediSource Lexicon; these are cross-indexed by RxNorm, which also assigns a unique identifier (RxCUI) to every combination of active ingredient and dose level.2
"National Drug Code Directory". U.S. Food and Drug Administration. 5 May 2017. https://www.fda.gov/Drugs/InformationOnDrugs/ucm142438.htm ↩
RxNorm Overview https://www.nlm.nih.gov/research/umls/rxnorm/overview.html ↩