IPEC: Updated Stability Guide for Excipients

At the end of March 2026, the IPEC (International Pharmaceutical Excipients Council Europe (IPEC Europe) asbl) announced the updated Version 3 of its 'Excipient Stability Guide for Pharmaceutical Excipients' in a notice on its website. This was first published in 2010 and is currently only available and viewable in the IPEC members' area. Following a three-month period (expected to end on 30 June 2026), the updated guide is due to be published in full. It is expected that, as usual, this will be available under the 'Resources' section in the 'Guidelines' area of the IPEC website. At present, the summary and table of contents are available for viewing.

This version has been expanded to include the following sections, for example:

• Stability studies: Data from three risk-based stability study designs were presented and compared
• Expansion of recommendations and practical implementations on the following topics:
  - Bracketing and matrixing
  - Transport stability studies, bulk storage, ongoing and accelerated stability studies, expiry dates and retest periods, specifications and their test parameters, special stability studies, e.g. for novel substances or substances used in biologics and vaccines
  - Harmonisation of terminology and reduction of redundancies
• The clear distinction between the requirements for excipients and active substances has been identified and presented.

The table of contents for the updated Version 3 of the Guide includes the following chapters, with Chapters 1, 2, and 3 containing further sub-chapters and sub-sections. An overview of the main chapters can be found here:

FOREWORD
ACKNOWLEDGEMENTS
1 INTRODUCTION
2 EXCIPIENT STABILITY PROGRAMMES
3 EXCIPIENT STABILITY OPTIONS
4 SHIPPING STUDIES
5 REFERENCES

The advance notice of Version 3 of the 'Excipient Stability Guide for Pharmaceutical Excipients (Version 3, 2026)' and the full table of contents can be found on the IPEC website.