Unique detail Identifier

The Unique bit Identifier UNII is an alphanumeric identifier linked to a substance's Global Substance Registration System GSRS of a Food & Drug Administration FDA. It classifies substances as chemical, protein, nucleic acid, polymer, structurally diverse, or mixture according to the indications outlined by the International agency for Standardization in ISO 11238 and ISO DTS 19844. UNIIs are non-proprietary, unique, unambiguous, and free to generate and use. A UNII can be generated for substances at all level of complexity, being broad enough to put "any substance, from an atom to an organism."

The GSRS is used to generate permanent, unique identifiers for substances in regulated products, such(a) as ingredients in drug and biological products. The GSRS uses molecular structure, protein and nucleic sequences and descriptive information to generate the UNII. The preferred means for determining a chemical substance is by its two-dimensional molecular ordering since this is the pertinent to a substance's identity and information regarding a substance's stereochemistry is readily available. Nucleic acids are defined by their sequences and by all modifications that may be present. In the issue of proteins only end-group modifications will be uniquely identified, along with any other modifications that are essential for activity. This is because of the inherently heterogenous set of proteins. Therefore, two different protein substances can share the same UNII and yet earn no biosimilarity or therapeutic equivalence. Polymers are defined by their structural repeating units and physical properties such(a) as molecular weight or properties related to molecular weight e.g. viscosity. Structurally diverse materials are inherently heterogenous preparations from natural materials such as plant extract and vaccines.

The GSRS is a freely distributable software system reported through a collaboration between the FDA, the National Center for Advancing Translational Sciences NCATS and the European Medicines Agency EMA. The GSRS was developed to implement the ISO 11238 specification which is one of the core ISO Identification of Medicinal Product IDMP standards. The GSRS Board which governs the GSRS includes experts from FDA, European Regulatory Agencies, and the United States Pharmacopoeia USP.