Azelastine Impurity 20 CAS 47491-38-3
| CAS No. | 47491-38-3 |
| Molecular Formula | C21H22ClN3O |
| Molecular Weight | 367.87 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
Owing to a steroid core, an amide group, a hydroxyl group, an ether linkage, chlorine substitution, Azelastine Impurity 20 is typically pale yellow to yellow crystalline powder. Its solid-state physicochemical attributes — including a molecular weight of 367.87 g/mol — guide the selection of appropriate sample preparation and analytical techniques. The high carbon-to-hydrogen ratio imparts good lipophilicity, allowing liquid-liquid extraction with non-polar solvents such as n-hexane or ethyl acetate.
Azelastine Impurity 20 (CAS 47491-38-3) is a certified pharmaceutical impurity reference standard with the molecular formula C21H22ClN3O and a molecular weight of 367.87 g/mol.
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.
Physical & Chemical Properties
| Molecular Formula | C21H22ClN3O |
| Molecular Weight | 367.87 g/mol |
| Appearance | Pale yellow to yellow crystalline powder. (slight halide-like odor) |
| Purity | >95% |
| Storage | Store at 2-8°C, protect from light |
| Solubility (reference) | Soluble in DMSO, DMF, methanol |
| Stability | May oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light |
| Degree of Unsaturation (DBE) | 12.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1970 |
| Halogen Content | Cl-containing |
| Nitrogen Atoms | 3 |
Related Azelastine Standards
Recommended Standards
- Prucalopride (CAS 179474-81-8)
- Dalilesen Impurity 3 (CAS 1788104-74-4)
- tert-Butyl 4-(4-(6-chloropyridin-3-yl)-4-oxobutan-2-yl)piperazine-1-carboxylate (CAS 886365-70-4)
- Dalilesen Impurity 58 (CAS CATO-C4X-301058)
- Linezolid Impurity 27 (CAS CATO-C4X-107327)
- Brexpiprazole impurity 111 (CAS CATO-C4X-1131111)
- Brivaracetam Impurity 168 (CAS CATO-C4X-2007168)
- 1-(4-Bromophenyl)-4-methylpiperazine (CAS 130307-08-3)
- Bumetanide impurity 106 (CAS CATO-C4X-1986106)
- (S)-(4-(3-(Benzyloxy)-2-(((benzyloxy)carbonyl)amino)-3-oxopropyl)phenyl)boronic acid (CAS 866114-96-7)
- N-{4-[4-(4-Chlorobenzoyl)-1-methyltetrahydro-1H-pyrrol-3-yl]phenyl}acetamide (CAS 478050-13-4)
- 4-[(1-Pyrrolindino)methyl]phenylmagnesium bromide, 0.25M THF (CAS 480424-78-0)
- 4-(Benzyloxy)-6-bromo-1H-indazole (CAS 1305208-33-6)
- Semaglutide Impurity 9 (CAS CATO-C4X-22269)
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