Implementation strategy of ICH Q3D guideline

The purpose of this document is to address specific considerations to enable the practical implementation of ICH Q3D Guideline for Elemental Impurities in the European Union. It is intended to provide guidance for Applicants/MAHs, drug product, drug substance and excipient manufacturers, as well as regulators. In addition to new applications, it will also apply to variations to existing authorised medicinal products. 

In the ICH Q3D Guideline for elemental impurities, the focus of the control of elemental impurities is shifted compared to the CHMP Guideline on the Specification Limits for Residues of Metal Catalysts or Metal Reagents1. Indeed: 

• the latter guideline focuses on control of metals intentionally added during the synthesis of the drug substance; 

• the former acknowledges that this is one of the most important sources of elemental impurities, but also takes into account other sources and therefore includes elements not used as catalysts and reagents. 

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