Glossary
What is ICH Q3A and Q3B?
International Council for Harmonisation guidelines on impurities in new drug substances (Q3A) and new drug products (Q3B). They set reporting, identification and qualification thresholds for organic impurities and degradation products, linked to the maximum daily dose. For a drug substance with a daily dose up to 2 g, for example, the identification threshold is generally 0.10% or 1 mg per day, whichever is lower.