Active ingredient · Phensuximide family
Pharmaceutical analytical standardPhensuximide
Synonyms: 1-methyl-3-phenylpyrrolidine-2,5-dione, Succitimal, Lifene, Milontin, Epimid, Milonton, Mirontin, Fensuccimide, Fensuximida, Succinimide, N-methyl-2-phenyl-, N-Methyl-alpha-phenylsuccinimide, NSC 760079, n-methyl-3-phenylpyrrolidinedione, Phensuccimide, Phenylsuximide, Fenosuccimide, Methylphenylsuccinimide, N-Methyl-2-phenylsuccinimide, Pharmakon1600-01505458, n-methyl-3-phenylsuccinimide
- Cat. No.
- P-P087-001
- CAS
- 86-34-0
- Alternative CAS
- 34367-67-4 (alternative CAS, same compound)
- Formula
- C11H11NO2
- Molecular weight
- 189.21 g/mol
- Category
- Active ingredient (API)
An antiepileptic of the succinimide class, first described in 1951 and used for absence (petit mal) seizures; within the same family, ethosuximide later became the reference drug.
Did you know?In 2025 a study found that it blocks the enzyme RIPK1, involved in an inflammatory form of programmed cell death called necroptosis: a possible new use, seen in cells and laboratory mice.
The two levels compared
| Level 1 Mass balance | Level 2 Mass balance + qNMR | |
|---|---|---|
| Identity (IR, MS, 1H and 13C-NMR; peptides: ESI-MS, MALDI-TOF and IR) | ✓ | ✓ |
| HPLC purity (min. 95%) | ✓ | ✓ |
| Content by mass balance (min. 90%; peptides: for information only)* | ✓ | ✓ |
| Content verified by qNMR (small molecules only) | · | ✓ |
| Suitable to qualify it as an in-house primary standard (ICH Q7) | · | ✓ |
* Mass balance is performed on every molecule. The only exceptions are cases where the chemistry of the molecule prevents it, for example oils and highly volatile substances, on which some of the required measurements cannot be made: in those cases the CoA states how the content was assigned.
What you receive
Shipped under controlled temperature when the molecule requires it.
For every lot: identity, purity and assay, with the supporting spectra and chromatograms.
Sent with every order.
Follow your shipment live, from our warehouse to your lab.
Frequently asked questions
Is mass balance always performed?
Yes, on every molecule. The only exceptions are cases where the chemistry of the molecule prevents it: for example oils and highly volatile substances, on which some measurements (such as thermogravimetry) cannot be made. In those cases the CoA states which method was used to assign the content.
Can I ask for a different quantity?
Yes. The quantities are only suggestions: choose "Other" and enter the milligrams or grams you need.
Which level should I choose?
Level 1 is enough for most routine testing. Level 2 adds an independent qNMR content value and is meant for labs that need to qualify an in-house primary standard. For peptides and similar molecules, Level 2 is not available.
When will I get the quote?
Within 24 working hours, with price, availability and delivery time.
Need a molecule you cannot find?
Custom synthesis of impurities, metabolites and labelled compounds, with the same characterisation level.