The purpose of the joint FDA/USP Substance Registration System (SRS) is to support health information technology initiatives by generating unique ingredient identifiers (UNIIs) for substances in drugs, biologics, foods, and devices. The UNII is a non- proprietary, free, unique, unambiguous, non semantic, alphanumeric identifier based on a substance’s molecular structure and/or descriptive information.

Prefix

unii

Links

Homepage

Pattern for Local Unique Identifiers

Local unique identifiers in Unique Ingredient Identifier should match this regular expression:
^[A-Z0-9]+$

Example Local Unique Identifier

3G6A5W338E   Resolve

Pattern for CURIES

Compact URIs (CURIEs) constructed from Unique Ingredient Identifier should match this regular expression:
^unii:[A-Z0-9]+$

Example CURIE

unii:3G6A5W338E

Contact

Missing Contact

Identifier Space Owner

United States Food and Drug Administration

A summary of the relations in the Semantic Farm schema can be found here.

In Collection (2)

FHIR External Terminologies Synapse.org external links

Mappings from records in Semantic Farm to external registries comprises the metaregistry. This resource has 5 mappings to external registries with 3 unique external prefixes.

A provider turns a local unique identifiers from a resource into a URI. Many providers are also resolvable as URLs (i.e., they can be used in a web browser).

The local unique identifier 3G6A5W338E is used to demonstrate the providers available for Unique Ingredient Identifier. Some providers may use a different example, which is displayed in the table below. A guide for curating additional providers can be found here.