rac-Clemastine Fumarate EP Impurity B HCl CAS 61771-18-4 (free base)
| CAS No. | 61771-18-4 (free base) |
| Molecular Formula | C21H26ClNO |
| Molecular Weight | N/A |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
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.
CATO supplies rac-Clemastine Fumarate EP Impurity B HCl (CAS 61771-18-4 (free base)), a pharmacopoeial impurity reference standard (molecular formula C21H26ClNOHCl, MW 380.35 g/mol) used for the identification and quantification of trace impurities in APIs.
The molecular framework of rac-Clemastine Fumarate EP Impurity B HCl (C21H26ClNOHCl) is characterized by a steroid core, an amide group, a hydroxyl group, an ether linkage, chlorine substitution. In reversed-phase chromatography, its retention is governed primarily by its high hydrophobicity (logP), which provides a practical basis for HPLC-UV/DAD or LC-MS method development. The aromatic system may exhibit native fluorescence, enabling detection with a fluorescence detector (FLD).
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.
Physical & Chemical Properties
| Molecular Formula | C21H26ClNO HCl |
| Molecular Weight | 380.35 g/mol |
| Appearance | Pale yellow to yellow crystalline powder. (slight halide-like odor, low volatility) |
| Purity | >95% |
| Storage | Store at 2-8°C, protect from light |
| 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) | 8.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| Halogen Content | Cl-containing |
| Nitrogen Atoms | 1 |
Related rac Standards
- Clemastine Impurity 27 (CAS 10095-17-7)
- Clemastine EP Impurity A(Mixture of Diastereomers) (CAS 108825-05-4)
- Clemastine Impurity 28 (CAS 1333340-87-6)
- Clemastine EP Impurity B (CAS 1352549-49-5)
- Clemastine fumarate (CAS 14976-57-9)
- Clemastine (CAS 15686-51-8)
- Clemastine Impurity 26 (CAS 171296-35-8)
- Clemastine Impurity 4 (CAS 20763-27-3)
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