Indometacin EP Impurity I CAS 16401-99-3
| CAS No. | 16401-99-3 |
| Molecular Formula | C21H20ClNO4 |
| Molecular Weight | 385.84 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
As a process- or degradation-related impurity, Indometacin EP Impurity I (CAS 16401-99-3, C21H20ClNO4) is essential for impurity profiling, related-substances testing, and forced-degradation studies in pharmaceutical development.
The molecular framework of Indometacin EP Impurity I (C21H20ClNO4) is characterized by a flavonoid core, an amide group, a hydroxyl group, an ether linkage, chlorine substitution. In reversed-phase chromatography, its retention is governed primarily by the protonation state of its nitrogen-containing groups, which provides a practical basis for HPLC-UV/DAD or LC-MS method development. The aromatic system may exhibit native fluorescence, enabling detection with a fluorescence detector (FLD).
Recommended for quantitative analysis by HPLC, GC, LC-MS/MS, or GC-MS as an external calibration standard; it can also be used for spiked-recovery experiments, LOD/LOQ determination, and LC-MS/MS multiple-reaction-monitoring (MRM) calibration.
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 | C21H20ClNO4 |
| Molecular Weight | 385.84 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 methanol, acetonitrile, DMSO, water (slightly soluble) |
| Stability | May oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light; 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.) | 1961 |
| Halogen Content | Cl-containing |
| Nitrogen Atoms | 1 |
Related Indometacin Standards
- Indometacin Impurity 55 (CAS CATO-C4X-147055)
- Indometacin EP Impurity G (CAS 402849-26-7)
- Indometacin EP Impurity H (CAS 1601-18-9)
- Indometacin EP Impurity D (CAS CATO-C4X-147012)
- Indometacin EP Impurity E (CAS 807614-94-4)
- Indometacin Impurity 47 (CAS CATO-C4X-147047)
- Indometacin Impurity 54 (CAS CATO-C4X-147054)
- Indometacin Impurity 65 (CAS CATO-C4X-147065)
Recommended Standards
- N-(2-Chlorophenyl)-2-(6-(4-fluorophenyl)imidazo[2,1-b]thiazol-3-yl)acetamide (CAS 897464-44-7)
- Tepoxalin (CAS 103475-41-8)
- Cisapride Impurity 1 (CAS 83863-70-1)
- Indisulam (CAS 165668-41-7)
- Naltrexone impurity 48 (CAS CATO-C4X-147548)
- Empagliflozin Impurity 6 (CAS CATO-C4X-10656)
- Lenvatinib Impurity 123 (CAS CATO-C4X-1140123)
- 121348-98-9 3,4-dichloro-n-[2-(dimethylamino)cyclohexyl]-n-methylbenzamide hcl (CAS 121348-98-9)
- 2-[(2-Chloro-6-fluorophenyl)methyl]-4-[(1E)-[(1-phenylethyl)imino]methyl]benzene-1,3-diol (CAS 338750-15-5)
- [(4-bromo-1-methyl-1H-pyrrol-2-yl)methyl](methyl)amine (CAS 1384596-71-7)
- N1-(4-Acetamidophenyl)-N2-cycloheptyloxalamide (CAS 900000-79-5)
- 4-([1,1'-Biphenyl]-2-yloxy)aniline (CAS 212189-56-5)
- 2-(Furan-3-yl)-4-oxo-4H-chromene-3-carboxylic acid (CAS 89002-87-9)
- Pancreatic Polypeptide (31-36) Free Acid, human (CAS 192432-73-8)
Why CATO?
- ISO 17034 accredited reference material producer (CNAS + ANAB dual accreditation)
- 130,000+ catalog items in stock, COA supplied with every batch
- Worldwide shipping with full export documentation (HS code guidance available)
- Technical support: +86 18665070610 / Nicole.chen@cato-chem.com