Stability study requirement-API

Hello all !! good morning.
I have a subject to be discussed regarding stability studies of API.

  1. Is it required to initiate stability study for an API after milling as per customer requirement. Already stability initiated for un-milled as per IH specification(Filed).
    If yes or no why?

  2. Can we consider transferring site stability data for assigning retest period by showing equipment equivalency.? How ever receiving site will initiate the stability study.

Hoping positive discussions.

Tattukolla Satya Babu

Yes! Stability is required per ICH rules on the finished drug substance which includes milling. Milling can introduce higher concentrations of a related substance(s) due to oxidation and increase in the surface area available for reactions.

Moving the site can be problematic. Even proving the process equipment is equivalent may not be adequate as a new related substance may be site specific. At least 1 lot should be put on stability to confirm your assumptions.