Demeclocycline Hydrochloride EP Impurity D CAS 81181-91-1
| CAS No. | 81181-91-1 |
| Molecular Formula | C21H20N2O7 |
| Molecular Weight | 412.39 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
Structurally, Demeclocycline Hydrochloride EP Impurity D (C21H20N2O7) contains a flavonoid core, an amide group, a hydroxyl group, an ether linkage. The molecule exhibits a degree of unsaturation (DBE) of 13.0, corresponding to approximately 13 ring(s) or double-bond equivalent(s). With a molecular weight of 412.39 g/mol, it falls into the moderately-high-molecular-weight range. The aromatic system may exhibit native fluorescence, enabling detection with a fluorescence detector (FLD).
As a process- or degradation-related impurity, Demeclocycline Hydrochloride EP Impurity D (CAS 81181-91-1, C21H20N2O7) is essential for impurity profiling, related-substances testing, and forced-degradation studies in pharmaceutical development.
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 | C21H20N2O7 |
| Molecular Weight | 412.39 g/mol |
| Appearance | Pale yellow to yellow crystalline powder |
| Purity | >90% |
| Storage | Store in a cool place (≤25°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 |
| Degree of Unsaturation (DBE) | 13.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1980 |
| Nitrogen Atoms | 2 |
Related Demeclocycline Standards
- Demeclocycline Impurity 10 (CAS CATO-C4X-160810)
- Demeclocycline EP Impurity E (CAS 4496-85-9)
- Demeclocycline impurity 12 (CAS CATO-C4X-160812)
- Demeclocycline EP Impurity A (CAS 987-02-0)
- Demeclocycline EP Impurity C (CAS 129044-45-7)
- Demeclocycline EP Impurity F (CAS CATO-C4X-16086)
- Demeclocycline EP Impurity G (CAS 22688-73-9)
- Demeclocycline EP Impurity B (CAS 14206-59-8)
Recommended Standards
- Warfarin impurity 11 (CAS CATO-C4X-17811)
- Picropodopyllotoxone (CAS 477-48-5)
- Celecoxib Impurity 65 (CAS CATO-C4X-104365)
- Ensitrelvir Impurity 6 (CAS 2771355-73-6)
- Bromfenac Impurity 24 (CAS 241825-88-7)
- Selexipag Impurity 71 (CAS CATO-C4X-196171)
- Vibegron Impurity 2 (CAS 136620-75-2)
- 1-(Dimethoxymethyl)naphthalene (CAS 33250-32-7)
- 4,4'-(2,2-Dichloroethene-1,1-diyl)bis(2-nitroaniline) (CAS 134292-37-8)
- tert-Butyl ((1-((S)-2-aminopropanoyl)piperidin-2-yl)methyl)(cyclopropyl)carbamate (CAS 1354028-60-6)
- 2-amino-N-[(2-chlorophenyl)methyl]-6-methylbenzene-1-sulfonamide (CAS 1155119-72-4)
- Methyl 2-(1,2,3,4-tetrahydroisoquinolin-5-yl)acetate (CAS 960354-11-4)
- 2-(((2-Amino-5-chlorophenyl)(phenyl)methylene)amino)ethan-1-ol (CAS 2109-45-7)
- Tau Peptide (275-305) (Repeat 2 Domain) trifluoroacetate salt (CAS 330456-25-2)
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