A pharmacopoeia revision is a standards question first
By Lu Chao, Sales Director · technical review by CATO technical documentation · Published · Last reviewed · Regulatory
Pharmacopoeial revisions are published as documents, but they arrive in a laboratory as work: a list of general chapters and monographs that changed, and a question about every reference standard already on the shelf.
The 2025 edition of the Chinese Pharmacopoeia has been in force since 1 October 2025. Revisions of that size touch the general chapters of Volume IV — the methods sections covering everything from residue testing to biological assays — and each touched method implies a standard that has to be re-qualified against it.
Three checks, in this order
1. Does the standard still match the method? A method chapter can change the system suitability requirement without changing the analyte. If the requirement is resolution between two closely eluting compounds, a standard that used to be adequate for identification may no longer be adequate for the check. Read the changed chapter for what it demands of the reference material — not just for what it demands of the instrument.
2. Is the assigned content current for the lot you hold? Content is assigned per lot and stated on the certificate for that lot. If the certificate you hold is three years old and the vial is nearly empty, the value in your method file may not be the value for the material you are weighing today. This is the single most common finding in a documentation review.
3. Is the traceability chain intact on paper? Catalogue number, lot number, assigned content, analytical basis, storage condition, and the safety data sheet with its transport classification. A standard that cannot be traced from the certificate to the vial in the run record is, for audit purposes, an unverified standard.
What to ask a supplier when a monograph changes
- Which lots are still valid, and what is the assigned content on each? A supplier who answers
"purity 98%" has not answered the question.
- Can the certificate for a specific lot be retrieved by lot number? If not, the lot in the run
record cannot be shown to be the lot that was qualified.
- What is the storage and shipping condition for this compound? It is a property of the compound,
not of the catalogue: a moisture-sensitive standard shipped ambient is a different material on arrival.
- What supporting data exists for identity? For a non-compendial impurity, the answer should include
the evidence behind the structure, not only a retention time.
What CATO does about it
Every lot CATO ships carries its own certificate of analysis, with the content assigned for that lot and the analytical method named. Typical purity or assay measured on a released lot is published on the product page for the majority of the catalogue, so a laboratory can see the value before it asks. Where a revised chapter needs a standard that no catalogue lists, the compound can be made — send the structure or the parent drug substance and we will confirm feasibility, pack size, lead time and the documentation that travels with it.
Start from the catalogue if you have a CAS number, from the CAS index if the number is all you were given, or from custom synthesis if the method needs something that is not listed anywhere.
*Background on the revision comes from CATO's own industry notes; the three checks above are the ones a laboratory controls itself. CATO does not publish prices — quotations are given per enquiry.*
Sources and further reading
- Chinese Pharmacopoeia Commission (accessed 2026-10-10): the revision and its general chapters are published there.
- ICH quality guidelines (accessed 2026-10-10): the method requirements referenced in this note.
- Related catalogue pages: reference standards by type · quality and documentation · COA lookup by catalogue number
Written by CATO. Where a claim depends on an external source we say which one; where it depends on our own catalogue we name the catalogue number so you can check it. Spotted an error? Email chao.lu@cato-chem.com — corrections are published in place.