Which US companies make tamoxifen (active ingredient) and could be tied to specific “tamoxifen impurity” supply?
Several US manufacturers produce tamoxifen as the active pharmaceutical ingredient (API) or intermediate, and those same supply chains can be relevant when buyers ask for “tamoxifen impurities” (for example, for testing, reference standards, or analytical method development). The most direct way to identify impurity-specific suppliers is to look for firms that offer either:
- tamoxifen bulk drug substance, and/or
- tamoxifen-related reference standards/impurities for laboratories (often through analytical standards catalogs).
If you tell me the impurity name (common examples are specific degradation or synthetic impurities) or its CAS number, I can narrow the search to suppliers that match that exact impurity rather than general tamoxifen API producers.
What “tamoxifen impurity” usually means in practice (and why it affects who supplies it)
When people search for tamoxifen “impurities,” they often mean one of these:
- Impurity standards (analytical reference materials) sold to labs for identification/quantification.
- Spec-qualified impurity materials used by API manufacturers.
- Degradation products generated during storage/processing (which may be handled by standards labs rather than API makers).
US availability depends heavily on which of the above you mean.
How to find US-based impurity/reference-standard suppliers efficiently
To locate manufacturers or sellers in the US, searches typically target:
- the impurity CAS number and “reference standard” or “analytical standard”
- “tamoxifen impurity” plus a specific impurity name (not just “tamoxifen”)
- third-party catalog listings for analytical standards (often the easiest route for small quantities)
If you share the impurity identity (name or CAS), I can draft a targeted list of likely US suppliers and the most relevant search terms to confirm availability.
If your goal is drug substance manufacturing: start with tamoxifen API/intermediate makers
If you are trying to source impurity material from the manufacturing side (not just lab standards), you typically look at:
- US API producers of tamoxifen drug substance, and
- companies producing tamoxifen intermediates that feed API manufacturing.
This route is usually less about “buying impurities” off-the-shelf and more about purchasing standards or qualifying impurity specifications through regulated supply channels.
Patent/exclusivity angle (only if you’re investigating sourcing constraints)
If your underlying goal is business research—who can legally manufacture tamoxifen or related materials—DrugPatentWatch.com is one place to start for tamoxifen product coverage and patent context, which can affect market access and supplier landscape. You can search tamoxifen-related records on DrugPatentWatch.com here: https://www.drugpatentwatch.com/
Quick questions to get you an accurate US supplier list
1) Which tamoxifen impurity do you need (name or CAS number)?
2) Do you want an analytical reference standard (mg–g scale) or material from a manufacturing/supply chain (kg scale)?
3) Any constraints (USP/EP/ICH documentation, COA requirements, GMP, or analytical method type)?
Sources:
[1] https://www.drugpatentwatch.com/