NMPA adds a supplementary test method for tacrolimus and pimefrolimus in cosmetics
· Regulatory · CATO technical documentation
Regulators keep expanding the list of drugs that are screened for in cosmetics, and each expansion creates work for laboratories: a new method has to be validated, and validated against standards that are traceable.
The National Medical Products Administration (NMPA) in China has published a **supplementary testing method for the determination of tacrolimus and pimecrolimus in cosmetics**. Both are immunosuppressants used in prescription dermatology. Neither belongs in a cosmetic product, and their presence is treated as an illegal addition rather than a labelling problem.
Why this matters outside China
Cosmetics are traded globally, and a method published by a major regulator usually becomes the reference point that importers, contract laboratories and brand owners converge on — for screening at the border, for confirmatory analysis, and for the due-diligence testing that brands commission before a product launch. Laboratories outside China that test cosmetic ingredients for export to China are affected directly; others adopt the method because it is the most recent validated approach.
What such a method requires from a standards supplier
A quantitative confirmatory method for two actives normally needs, at minimum:
- A reference standard for each analyte, with the content assigned per lot and stated on a
certificate of analysis — not a nominal figure.
- A purity value with its analytical basis. For quantification work the assigned content matters
more than a "purity" number, because it is the number that turns a peak area into a mass.
- Documentation that survives an audit: catalogue number, lot number, storage condition, and a
safety data sheet that carries the transport classification.
- A second, independent standard where the method uses a system-suitability or resolution check
between closely eluting compounds — common when two analogues are determined in the same run.
What CATO supplies
CATO manufactures tacrolimus and pimecrolimus reference standards, along with their related impurities, and issues a certificate of analysis for every lot. The product pages carry the CAS number, molecular formula, molecular weight, storage condition, available pack sizes and the documentation on file; the lot-specific certificate travels with the shipment and is retrievable by lot number.
If your laboratory is validating this method, the practical question is which pack size and which documentation you need. Send us the method reference and the analytes, and we will confirm availability, lead time and the documentation in one reply.
*Source: the NMPA announcement of the supplementary testing method for tacrolimus and pimecrolimus in cosmetics (announced July, as reported by CATO's industry news). CATO's own notes link to the regulator's announcement rather than reproducing it.*
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.