| CAS No. | 161885-78-5 |
| Molecular Formula | C38H68O4Si2 |
| Molecular Weight | 645.12 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
The occurrence of Calcitriol impurity 39 is closely related to a carboxylic acid group, a hydroxyl group, an ether linkage, an aromatic ring system in its molecular formula, which determines its behaviour during synthesis, purification, or degradation.
Calcitriol impurity 39 (CAS 161885-78-5) is a certified pharmaceutical impurity reference standard with the molecular formula C38H68O4Si2 and a molecular weight of 645.12 g/mol.
Structurally, Calcitriol impurity 39 (C38H68O4Si2) contains a carboxylic acid group, a hydroxyl group, an ether linkage, an aromatic ring system. The molecule exhibits a degree of unsaturation (DBE) of 5.0, corresponding to approximately 5 ring(s) or double-bond equivalent(s). With a molecular weight of 645.12 g/mol, it falls into the high-molecular-weight range. 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 | C38H68O4Si2 |
| Molecular Weight | 645.12 g/mol |
| Purity | 97%+ |
| Storage | Store at room temperature, keep sealed and dry |
| Solubility (reference) | Soluble in chloroform, dichloromethane, ethyl acetate, DMSO |
| Stability | May oxidize slowly on prolonged air exposure |
| Degree of Unsaturation (DBE) | 5.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 2003 |