| CAS No. | 171752-68-4 |
| Molecular Formula | C20H18N2O4 |
| Molecular Weight | N/A |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Based on its molecular formula C20H18N2O4HCl, Tadalafil Impurity 20 contains a flavonoid core, an amide group, a hydroxyl group, an ether linkage, chlorine substitution; these features give the compound characteristic absorption bands in UV spectroscopy. The molecular weight of 386.83 g/mol is directly relevant to the identification of the molecular ion in mass spectrometry. The aromatic system may exhibit native fluorescence, enabling detection with a fluorescence detector (FLD).
Tadalafil Impurity 20 (CAS 171752-68-4) is a certified pharmaceutical impurity reference standard with the molecular formula C20H18N2O4HCl and a molecular weight of 386.83 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.
CATO manufactures Tadalafil Impurity 20 under ISO 17034:2016 accreditation with dual CNAS and ANAB accreditation. Each batch is characterized by orthogonal methods and supplied with a full Certificate of Analysis (COA), ensuring metrological traceability.
| Molecular Formula | C20H18N2O4 HCl |
| Molecular Weight | 386.83 g/mol |
| Appearance | Pale yellow to yellow crystalline powder. (slight halide-like odor) |
| Purity | >95% |
| Storage | Store at 2-8°C, protect from light, keep sealed and dry |
| Solubility (reference) | Soluble in DMSO, DMF, methanol |
| Stability | May oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light; Hygroscopic; reseal immediately after opening; Contains ester bond; hydrolyzes under strong alkaline conditions |
| Degree of Unsaturation (DBE) | 12.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 2006 |
| Halogen Content | Cl-containing |
| Nitrogen Atoms | 2 |