Best Practices in Impurity Qualification Study Design, 3R Considerations (S13-3)

Pharmaceutical impurities are generally qualified in the general toxicology studies that are conducted
for the drug substance. In some instances, when a new impurity is identified or an impurity is observed
at higher levels than originally qualified, dedicated impurity qualification toxicology studies may need to
be conducted. Current regulatory guidelines do not specify details about the study design for such an
impurity qualification study, resulting in various study designs being used throughout the industry.
Based on the results of an IQ DruSafe Impurity-related survey, harmonized impurity qualification study
designs were created with a focus on patient safety while emphasizing the 3Rs (Replacement,
Reduction, Refinement of animal use). This presentation will cover learnings from industry on impurity
qualification study best practices as well as presents the harmonized study designs in terms of species
selection, recommended study design, and study duration among other study design considerations.