Expiration dating changes stability requirements

Approved stability protocols are important for the sponsor because they may be used in developing data to support an extension of an approved retest or expiration dating period via annual reports in accordance with 21CFR314.70(d)(5). To change an approved stability protocol or to define one in an application requires a prior approval supplement. 

For post-approval changes, the previously approved expiration date can be used unless the change will alter the stability of the product. Since the goal of most changes is to show that the changed product and pre-change product are equivalent, the approved expiration is typically proposed based on the required stability data for the change. 

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