USP Reference Standards—An Overview

What are Reference Standards?

USP's official Reference Standards are highly characterized specimens of drug substances, excipients, impurities, degradation products, dietary supplements, compendial reagents, and performance calibrators. They are specified for use in conducting official USP–NF tests and assays. USP also provides Reference Standards specified in the Food Chemicals Codex as well as authentic substances—high-quality chemical samples—as a service to analytical, clinical, pharmaceutical, and research laboratories. USP's Reference Standards are used in more than 130 countries around the world.

Certified Reference Materials (CRMs)

USP also offers CRMs, which represent the next generation of exceptional quality USP Reference Standards. They have undergone additional metrologically based testing and statistical analysis to meet both USP's stringent criteria and guidelines established by the International Organization for Standardization (ISO). Learn more about CRMs.

Applications

USP Reference Standards are designated for use in

  • Identification tests
  • Limit tests for impurities or related compounds
  • Assays for drug substances and for formulations
  • System suitability tests
  • Chromatographic and spectrophotometric procedures
  • Performance verification tests (e.g., particle count, melting point, and standardization of titrants) as calibrators, blanks, and controls

Official recognition

USP Reference Standards that are based directly on official monographs in the USP–NF—whose standards and procedures are enforceable by the U.S. Food and Drug Administration (FDA)—are recognized as official standards in the U.S., and their use is effective in demonstrating compliance with statutory requirements.

Developed through collaboration

USP Reference Standards are established through a collaborative testing process that involves at least three independent labs. Learn about the development process and how you can participate in it.

Helpful Tools and Resources

To assist you with your use of USP Reference Standards, USP offers a variety of tools and related resources. See the right sidebar for additional items.