Guidelines for the assessment and control of mutagenic impurities in pharmaceuticals

Pharmaceuticals may contain trace impurities unrelated to therapeutic activity, whICH may occur as synthetic intermediates or degradation products. Among these impurities, mutagenic impurities are of particular concern, as even very low levels of exposure can increase the risk of cancer in humans. To address this issue, the International Council on Harmonization (ICH) developed the M7 guideline in 2014, whICH aim to provide a scientific and practical framework for the assessment and control of mutagenic impurities in pharmaceuticals. The M7 guideline has been updated twice, in 2017 (R1) and 2023 (R2), with the addition of addendum defining compound-specific acceptable intake levels and a comprehensive Q&A document to promote harmonized implementation. Recent cases involving N-nitrosamine impurities have highlighted the need for improved risk assessment methods due to their high carcinogenic potential. The latest revision of the M7 guidelines (M7(R3)) will introduce a new approach to consider the quantitative carcinogenic potential of N-nitrosamines based on their structural characteristics.