Do you mean reference standards for rivastigmine impurities (for analytical method development like HPLC/LC-MS), or actual impurity compounds produced by manufacturers? Also, are you looking for US-based suppliers specifically?
If you’re after rivastigmine impurity reference standards (common in pharma QA/QC), these US-based vendors frequently carry them (availability can vary by impurity and grade):
- MilliporeSigma (Merck) – Certified reference standards and impurity standards for rivastigmine are often listed under rivastigmine impurity standards or related catalogs. They’re a primary source for pharma-grade reference materials.
- Cerilliant (a Thermo Fisher subsidiary) – Specializes in certified reference standards (CRMs) and often offers rivastigmine and potential impurity standards. Good option if you need COA-backed materials.
- LGC Standards – Broad catalog of pharmaceutical reference standards, including rivastigmine and various impurity standards. US distribution typically available.
- AccuStandard – Known for a wide range of impurity/CRM standards, including those for rivastigmine-type compounds.
- VWR / Avantor – Carries reference standards through its catalog; worth checking for rivastigmine impurities or related standards.
- Toronto Research Chemicals (TRC) – Canadian supplier that ships to the US; commonly stocks rivastigmine and impurity standards.
- USP (United States Pharmacopeia) – Provides official rivastigmine reference materials and related RS/impurities in many cases; note these are typically procured through USP or authorized distributors.
Notes and tips:
- Impurity catalog names and exact impurity designations (e.g., Rivastigmine impurity A, B, C, etc.) vary by vendor. If you know the exact impurity IDs from your method development (or ICH Q3A/B impurity names), include those when you inquire.
- Availability can depend on regulatory grade (ACS, HPLC-grade, USP RS, etc.) and required purity.
- If you need more than one impurity, some vendors offer bundles or allow custom synthesis of specific impurity standards.
If you can share:
- Which impurities (A, B, C, or specific designations) you need,
- Desired grade (USP RS, ACS, HPLC grade, COA requirements),
- Your target purity and packaging (mg, g, or larger),
I can help narrow down exact product names and draft inquiry messages to suppliers.