| CAS No. | 13391-39-4 |
| Molecular Formula | C13H10Cl2 |
| Molecular Weight | 237.12 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
The occurrence of Cetirizine Impurity C18 is closely related to chlorine substitution, an aromatic ring system in its molecular formula, which determines its behaviour during synthesis, purification, or degradation.
CATO supplies Cetirizine Impurity C18 (CAS 13391-39-4), a pharmacopoeial impurity reference standard (molecular formula C13H10Cl2, MW 237.12 g/mol) used for the identification and quantification of trace impurities in APIs.
Structurally, Cetirizine Impurity C18 (C13H10Cl2) contains chlorine substitution, an aromatic ring system. The molecule exhibits a degree of unsaturation (DBE) of 8.0, corresponding to approximately 8 ring(s) or double-bond equivalent(s). With a molecular weight of 237.12 g/mol, it falls into the medium-molecular-weight range. 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.
CATO manufactures Cetirizine Impurity C18 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 | C13H10Cl2 |
| Molecular Weight | 237.12 g/mol |
| Purity | 97%+ |
| Storage | Store at 2-8°C, protect from light, keep tightly closed to prevent evaporation |
| Solubility (reference) | Soluble in chloroform, dichloromethane, ethyl acetate |
| 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 |
| CAS Registry Year (est.) | 1960 |
| Halogen Content | Cl-containing |