Reference Standard
| CAS Number | Not assigned |
| Formula | Zafirlukast-related derivative |
| Molecular Weight | ~560–600 g/mol |
| Purity | ≥95% |
| Storage | Refrigerated; light-protected |
A specified related substance of zafirlukast formed through side-reaction or degradation pathways.
Stability studies, regulatory impurity control, and QC testing.
HPLC/UPLC, LC-MS/MS, retention-time comparison with reference standard.
