Drug safety and efficacy are inextricably linked to quality.

Identifying and properly controlling impurities are central to maintaining the quality of a drug as it moves from development to manufacture to release and throughout its shelf-life. Impurities can arise during the manufacturing process, storage, or degradation of a drug substance or product. If drug impurities are determined to be toxic, their presence—even in small amounts—can impact drug safety. Impurities can also impact product stability, with changes in impurity levels over time potentially affecting a drug’s potency and its ability to deliver its intended therapeutic benefit. 

As advances in chromatographic, spectroscopic, and other analytical methods have led to more comprehensive impurity characterization capabilities, confidence in a drug’s impurity profile has become synonymous with confidence in its continued quality.

USP-NF monographs are an essential tool in drug impurity profiling. Within their specifications for meeting regulatory standards for quality, USP-NF monographs contain impurity tables identifying critical impurities. Drug substance monograph tables list process-related impurities and degradation impurities, and tables in dosage form monographs include degradation products. Monograph tables feature relative retention times, relative response factors, and acceptance criteria (NMT%) for listed impurities which, when used with USP Pharmaceutical Analytical Impurities (PAIs) and/or USP Reference Standards, help gain an accurate impurity profile. Development of methods that are suitable and robust to properly analyze impurities requires well-characterized reference materials. Finding dependable and trustworthy suppliers of impurity reference materials can be a major hurdle for any drug developer or manufacturer. Lack of available impurity materials can slow down analytical method development, costing time and money and increasing the risk of product release or approval failure. 

USP PAIs* are best suited for—but not limited to—use in early method development and validation. PAIs listed in USP’s growing catalog of impurity reference materials (including process impurities, degradants, and nitrosamines) are immediately available for purchase. To see our full PAI catalog, click here. 

Supported by detailed Product Information Sheets, USP PAIs, together with USP API Reference Standards, USP Impurity Reference Standards, and USP-NF monographs as well as general chapters, provide a comprehensive solution for your impurity profiling needs. 

The impurity profile of your drug can make all the difference in the successful release or approval of your product.