USP Grade (United States Pharmacopeia) chemicals

What USP grade means

USP grade means a substance complies with its monograph in the United States Pharmacopeia–National Formulary (USP–NF), published by the United States Pharmacopeial Convention. Drug substance monographs appear in the USP, while most excipient monographs appear in the NF, which is why excipients are often labelled NF. Under US law, a drug or ingredient with a USP–NF monograph is expected to comply with it, and the US Food and Drug Administration enforces compendial standards. The USP–NF is updated continuously through official publications, so the COA should reference the current official text.

What a USP monograph specifies

• Definition and assay limits
• Identification tests, often using USP Reference Standards
• Impurity tests: organic impurities, residual solvents (General Chapter <467>), elemental impurities (<232> and <233>)
• Specific tests such as water, residue on ignition, pH or particle size
• Packaging, storage and labelling requirements

Typical specification profile

Parameter	Example: sodium bicarbonate USP
Assay	99.0 to 100.5% (dried basis)
Loss on drying	≤ 0.25%
Insoluble substances, carbonate, chloride, sulfate	Within monograph limits
Elemental impurities	Controlled in line with USP <232> and ICH Q3D

Values in the table are typical of the grade. The limits that apply to a given product are those stated on its specification and lot Certificate of Analysis.

Where it is used

USP-grade materials are used in medicines for the US market, in development laboratories performing USP methods, and increasingly as a quality benchmark in other markets. Dietary supplement ingredients may also have USP monographs.

How it differs from neighbouring grades

Ph. Eur., BP and IP grades are tested to different pharmacopoeias. Harmonised general chapters reduce but do not remove differences. FCC grade, also published by USP, covers food ingredients rather than drugs. ACS and AR are reagent grades without drug-compendial standing. Note that USP grade describes the material, while USP Reference Standards are separate, officially issued materials used to perform compendial tests.

Documentation

For USP-grade supplies, we provide a lot COA referencing the monograph and can request manufacturer statements on residual solvents, elemental impurities and nitrosamine risk where available.