Tretinoin EP Impurity F (4-Methoxy Retinoic Acid) CAS 81121-20-2
| CAS No. | 81121-20-2 |
| Molecular Formula | C21H30O3 |
| Molecular Weight | 330.46 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
The assigned purity is verified by mass-balance and quantitative NMR (qNMR) approaches, with the expanded uncertainty reported at a 95% confidence level (k=2). Batch homogeneity and stability are independently assessed for every lot.
CATO supplies Tretinoin EP Impurity F (4-Methoxy Retinoic Acid) (CAS 81121-20-2), a pharmacopoeial impurity reference standard (molecular formula C21H30O3, MW 330.46 g/mol) used for the identification and quantification of trace impurities in APIs.
Tretinoin EP Impurity F (4-Methoxy Retinoic Acid) (C21H30O3) contains a steroid core, a hydroxyl group, an ether linkage. Its high carbon-to-hydrogen ratio confers good lipid solubility, the carboxyl group imparts weak acidity; these physicochemical properties determine the optimal preparation and storage of its standard solutions. The presence of an aromatic ring or conjugated system gives the compound characteristic absorption bands in the UV-Vis region, making it well suited to UV or diode-array detection (DAD).
This reference standard supports related-substances testing and method development in line with ICH Q3A/Q3B guidance on impurity control, and is suitable for system suitability testing and forced-degradation studies.
Physical & Chemical Properties
| Molecular Formula | C21H30O3 |
| Molecular Weight | 330.46 g/mol |
| Appearance | Off-white to pale yellow crystalline powder |
| Purity | >95% |
| Storage | Store at 2-8°C, protect from light, keep sealed and dry |
| Solubility (reference) | Soluble in chloroform, dichloromethane, ethyl acetate, DMSO |
| Stability | May oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light |
| Degree of Unsaturation (DBE) | 7.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1980 |
Related Tretinoin Standards
- Tretinoin Impurity 12 (CAS 3899-20-5)
- Tretinoin Impurity 24 (CAS CATO-C4X-196924)
- Tretinoin Impurity 29 (CAS 129454-96-2)
- Tretinoin Impurity 10 (CAS CATO-C4X-196910)
- Tretinoin Impurity 8 (CAS CATO-C4X-19698)
- Tretinoin EP Impurity G (CAS 13100-69-1)
- 4-Oxo Tretinoin (4-Oxo Retinoic Acid) (CAS 38030-57-8)
- Tretinoin-d5 (CAS CATO-C4X-196937)
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