USP Expands Support for Controlling Impurities in Medicines

New Portfolio of Pharmaceutical Analytical Impurities Supports Drug R&D and Method Development

USP Contact
Anne Bell:
Office: +1-301-998-6785
Mobile: +1-703-334-1193

Rockville, MD, October 19, 2022 – The U.S. Pharmacopeia (USP) has launched a new portfolio of impurities materials to support pharmaceutical manufacturers' efforts to accelerate and strengthen analytical R&D and process development. USP Pharmaceutical Analytical Impurities (PAIs) support impurity analysis and profiling requirements during drug development and throughout the product lifecycle.

Changes in the pharmaceutical industry, including new manufacturing processes, more complicated drug formulations and an increasingly complex global supply chain, are making it more difficult for companies to assess and control for impurities. Beginning in 2018, a spate of drug recalls due to nitrosamine impurities has heightened awareness and attention on the potential consequences of impurities in medicines. Growing scrutiny of impurities by different regulators throughout the world is creating uncertainty for companies trying to bring new products to market.

In conversations with pharmaceutical industry leaders, USP’s John Giannone, Vice President of Industry Programs, confirmed the challenge of having impurities available during the drug development and manufacturing process. “Pharmaceutical manufacturers have told us time and again, that getting the impurities they need when they need them, can be difficult. But that it’s critical for advancing their analytical R&D and process development.”

Manufacturers can use PAIs for a wide spectrum of impurity analysis and profiling methods used in R&D, method development, manufacturing, quality control, stability testing and post-market surveillance. Applications include:

  • analytical testing during early formulation feasibility studies
  • determining degradation impurities produced during stress studies
  • identifying unknown impurities that formed during ICH stability conditions
  • developing, validating and transferring analytical methods
  • testing and profiling impurities not listed in monographs of drug substances and drug products

“This line of products dramatically widens the aperture of support that we provide to pharmaceutical manufacturers,” says Venkat Surendra Nath Koduru, USP’s Senior Vice President for Regions and Program Operations. “In pharmaceutical manufacturing, impurities can be a problem from start to finish. Using PAIs along with official USP Reference Standards, manufacturers can be confident in their analytical methods.”

USP’s technical experience is grounded in standards development for thousands of drug substances and finished dosage forms marketed worldwide, helping safeguard medicine quality.

U.S. law expressly recognizes USP quality standards for medicines. Drug products marketed in U.S. are expected to meet quality specifications in more than 4,000 monograph standards in USP-NF. Pharmaceutical manufacturers and government regulators rely on official USP Reference Standards for drug ingredients, finished drug products and impurities to provide a benchmark for quality.

The new PAI product line, while not required for compendial compliance, makes available additional impurities listed in monographs that do not have an official USP Pharmacopeial Reference Standard. The PAI catalogue also includes impurities for which there currently is not an associated drug monograph.

PAIs are released using a process developed by USP technical experts based on internal policies, standard operating procedures and requirements defined by USP’s Quality Management System. The current catalog includes more than 200 impurities, with more in development. The Product Information Sheet that accompanies each PAI provides details on the impurity’s identity and purity, further building manufacturers’ confidence in their analytical methods. For more information or to purchase USP PAI impurities, please visit the USP Pharmaceutical Analytical Impurities webpage.

About USP
USP is an independent scientific organization that collaborates with the world's top experts in health and science to develop quality standards for medicines, dietary supplements, and food ingredients. USP’s standards are used in the U.S. and other countries to ensure the quality of thousands of products including cardiovascular, oncology, endocrine and antibiotic drugs. Through its standards, advocacy, and education, USP helps increase the availability of quality medicines, supplements, and food for billions of people worldwide. For more information, visit