Pharmaceutical Analytical Impurities

Be confident in your analytical R&D and process development

Pressure to get your product to market – on time and on budget – is high. It can be tempting to “not sweat the small stuff.” But when it comes to impurities, those little peaks on your chromatogram can grow into big problems down the road. Building quality into the earlier stages of the product development and manufacturing lifecycle can save time and resources in the long run.

Impurities in pharmaceutical R&D and manufacturing are a fact of life. New manufacturing processes, more complex drug formulations and increasingly complicated global supply chains for materials and ingredients are making it more difficult for companies to assess and control for impurities. In addition, a spate of recalls due to unsafe levels of impurities has prompted regulators to scrutinize impurities more critically than ever and regulatory actions related to impurities continue to grow.

Finding and addressing impurities earlier in R&D and process development can reduce the risk of unsafe impurity levels later in manufacturing processes, helping you stay on time and in compliance with regulatory expectations.

analytical impurities

USP's Pharmaceutical Analytical Impurities

Understand your impurity profile and build quality earlier into your process through better design control

Buy impurities

Download PAI Catalog

USP and global regulators collaborate

U.S. FDA and many international regulators rely on USP standards and science-based solutions – including those for impurities – for drug approvals and post-market surveillance.

USP, U.S. FDA and global regulators collaborate to jointly drive solutions towards our shared commitment to medicine quality. Over 200 U.S. FDA staff serve on USP Expert Committees and Panels responsible for scientific development of USP standards, including impurity limits.

Under U.S. law, drug products marketed in the U.S. are expected to meet quality specifications in more than 4000 monograph standards in USP-NF, including tests for impurities using 1,500 impurity Reference Standards available from USP.

Our growing catalogue of impurities and reference standards

In addition to official USP Pharmacopeial Reference Standards for impurities, we now offer a growing catalogue of impurities through our Pharmaceutical Analytical Impurities (PAI) product line.

Assess and control for impurities
Assess and control for impurities throughout the entire drug lifecycle
  • R&D
  • method development
  • manufacturing
  • quality control
  • stability testing
  • post-market surveillance

Buy pharmacopeial reference standards

official compendial reference standards
Strengthen analytical R&D and process development
  • conduct analytical tests during early formulation feasibility studies
  • perform spiking studies during process R&D to demonstrate depletion upon recrystallization
  • retention times and/or spectra
  • determine relative response factors
  • determine degradation impurities produced during stress studies
  • identify unknown impurities that formed during ICH stability conditions
  • identify impurities which are present in the Reference Listed Drug
  • develop, validate and transfer analytical methods
  • test for and profile impurities not listed in drug substance and drug product monographs

Buy impurities

USP’s catalog of Pharmaceutical Analytical Impurities is growing rapidly. Please tell us about the APIs for which available impurities would have the most benefit to your work. Connect with your USP Account Manager or email us at