The threshold would be specific to each dosage form.
------------------------------
Tom Stothoff
Senior Director, Regulatory Affairs CMC
Chicago
------------------------------
Original Message:
Sent: 13-Aug-2023 18:01
From: Anonymous Member
Subject: ICHQ3B Impurities in new drug product
This message was posted by a user wishing to remain anonymous
Hi
According to ICH Q3B impurity threshold in a drug product is calculated based on the maximum amount of drug substance administered daily. Is the amount of substance for that particular product at a particular strength, particular route of administration or the maximum daily intake from any dose form or route of administration?
For example, suppose I have a 0.4% eye drop solution that is also available as a 4% eye drop solution and a 10 mg tablet. What is the maximum daily dose for the calculation of the impurity threshold?
Thank you
Zara