| CAS No. | 58380-11-3 |
| Molecular Formula | C7H5BrO3 |
| Molecular Weight | 217.02 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Under current pharmacopoeial and regulatory frameworks, quality-control requirements for this class of reference material explicitly involve the control of targets including Crisaborole Impurity 43.
CATO supplies Crisaborole Impurity 43 (CAS 58380-11-3), a pharmacopoeial impurity reference standard (molecular formula C7H5BrO3, MW 217.02 g/mol) used for the identification and quantification of trace impurities in APIs.
The molecular framework of Crisaborole Impurity 43 (C7H5BrO3) is characterized by a carboxylic acid group, a hydroxyl group, an ether linkage, bromine substitution, an aromatic ring system. In reversed-phase chromatography, its retention is governed primarily by the polarity and ionization state of its functional groups, which provides a practical basis for HPLC-UV/DAD or LC-MS method development. Halogen substitution (F/Cl/Br/I) produces a distinctive isotope pattern in mass spectrometry, a valuable aid for qualitative confirmation.
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.
As a certified reference material (CRM), Crisaborole Impurity 43 meets the metrological traceability requirements of ISO/IEC 17025 laboratories. Batch-to-batch consistency is monitored via control charts to guarantee comparable assigned values across lots.
| Molecular Formula | C7H5BrO3 |
| Molecular Weight | 217.02 g/mol |
| Appearance | Off-white to pale yellow crystalline powder. (slight halide-like odor) |
| Purity | >95% |
| Storage | Store in a cool place (≤25°C), keep sealed and dry, keep tightly closed to prevent evaporation |
| Solubility (reference) | Soluble in methanol, ethanol, DMSO, water |
| Stability | May oxidize slowly on prolonged air exposure; Hygroscopic; reseal immediately after opening; Contains ester bond; hydrolyzes under strong alkaline conditions |
| Degree of Unsaturation (DBE) | 5.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1973 |
| Halogen Content | Br-containing |