| CAS No. | CATO-C4X-2021158 |
| Molecular Formula | C16H15BrO3 |
| Molecular Weight | 335.19 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Compared with other compounds in its class, the molecular weight of 335.19 g/mol gives Crisaborole impurity 158 distinctive chromatographic separation conditions and mass-spectrometry parameter settings.
CATO supplies Crisaborole impurity 158 (CAS CATO-C4X-2021158), a pharmacopoeial impurity reference standard (molecular formula C16H15BrO3, MW 335.19 g/mol) used for the identification and quantification of trace impurities in APIs.
Crisaborole impurity 158 (C16H15BrO3) contains a carboxylic acid group, a hydroxyl group, an ether linkage, bromine substitution, a polycyclic aromatic system. Halogen substitution raises its density and boiling point, 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 high carbon-to-hydrogen ratio imparts good lipophilicity, allowing liquid-liquid extraction with non-polar solvents such as n-hexane or ethyl acetate.
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.
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.
| Molecular Formula | C16H15BrO3 |
| Molecular Weight | 335.19 g/mol |
| Appearance | Pale yellow to yellow crystalline powder. (slight halide-like odor) |
| Purity | 97%+ |
| 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; Contains ester bond; hydrolyzes under strong alkaline conditions |
| Degree of Unsaturation (DBE) | 9.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| Halogen Content | Br-containing |