Phenytoin impurities and related standards
3 reference standards related to Phenytoin held in the RSSE catalogue — pharmacopoeial impurities, non-compendial impurities, metabolites and labelled analogues where available.
CAS numbers are listed for 3 of 3; 3 entries carry a structure drawing.
| Compound | CAS No. | Catalogue No. | Formula | MW |
|---|---|---|---|---|
| Phenytoin EP Impurity A | 119-61-9 | RS-P072001 | C13H10O | 182.22 |
| Phenytoin EP Impurity B | 134-81-6 | RS-P072002 | C14H10O2 | 210.23 |
| (+/-)-4-Hydroxy Mephenytoin | 61837-65-8 | RS-P072003 | C12H14N2O3 | 234.25 |
Structures
-
Phenytoin EP Impurity A
COA per lot -
Phenytoin EP Impurity B
COA per lot -
(+/-)-4-Hydroxy Mephenytoin
COA per lot
Frequently asked
How many Phenytoin-related reference standards do you hold?
3 standards are listed on this page as of the latest catalogue build. CAS numbers are published for 3 of them and 3 entries carry a structure drawing. The catalogue is extended as new lots are released.
Can you supply a Phenytoin impurity that is not listed here?
Yes. Non-compendial impurities can be quoted from a structure — a CAS number is not required. Send the structure, a SMILES string or the parent drug substance with your enquiry and we will come back with availability.
What documentation is supplied with Phenytoin impurities?
Every lot ships with its own certificate of analysis. The certificate records the catalogue number, the batch number, the tests performed, the specification applied and the result obtained for that lot. A safety data sheet is supplied with the shipment.
Do you publish prices or a lead time for Phenytoin impurities?
No price list is published: quotations are prepared per enquiry, because availability and packing depend on the lot and the quantity you need. Send the catalogue number and the quantity and a technical contact will answer with availability and a quotation.
Cannot find the impurity you need? Non-compendial impurities can be quoted from a structure — a CAS number is not required. Write to sales@rssechem.com.


