Levothyroxine Impurity 18 CAS 1155-40-4
| CAS No. | 1155-40-4 |
| Molecular Formula | C14H10I2O4 |
| Molecular Weight | 496.04 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
The molecular framework of Levothyroxine Impurity 18 (C14H10I2O4) is characterized by a carboxylic acid group, a hydroxyl group, an ether linkage, iodine substitution, a polycyclic aromatic system. In reversed-phase chromatography, its retention is governed primarily by its high hydrophobicity (logP), which provides a practical basis for HPLC-UV/DAD or LC-MS method development. The high carbon-to-hydrogen ratio imparts good lipophilicity, allowing liquid-liquid extraction with non-polar solvents such as n-hexane or ethyl acetate.
CATO supplies Levothyroxine Impurity 18 (CAS 1155-40-4), a pharmacopoeial impurity reference standard (molecular formula C14H10I2O4, MW 496.04 g/mol) used for the identification and quantification of trace impurities in APIs.
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.
As a certified reference material (CRM), Levothyroxine Impurity 18 meets the metrological traceability requirements of ISO/IEC 17025 laboratories. Batch-to-batch consistency is monitored via control charts to guarantee comparable assigned values across lots.
Physical & Chemical Properties
| Molecular Formula | C14H10I2O4 |
| Molecular Weight | 496.04 g/mol |
| Appearance | Pale yellow to yellow crystalline powder. (slight halide-like odor, low volatility) |
| Purity | >95% |
| Storage | Store in a cool place (≤25°C), protect from light, keep sealed and dry |
| Solubility (reference) | Soluble in chloroform, dichloromethane, ethyl acetate, DMSO |
| 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) | 9.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1957 |
| Halogen Content | I-containing |
Related Levothyroxine Standards
- Levothyroxine Impurity 38 (CAS 1027-28-7)
- Levothyroxine Impurity 16 (CAS 4192-14-7)
- rac-Levothyroxine EP Impurity J (3,3'-DL-Diiodothyronine) (CAS 70-40-6)
- Levothyroxine EP Impurity J (CAS 4604-41-5)
- Levothyroxine EP Impurity E (CAS 1041-01-6)
- Levothyroxine Impurity 37 (CAS 94345-95-6)
- Levothyroxine Impurity 43 (CAS 854646-83-6)
- Levothyroxine Impurity 36 (CAS 100130-56-1)
Recommended Standards
- Indometacin Impurity 38 (CAS CATO-C4X-147038)
- 4-(5-Bromo-3-(bromo(2-chlorophenyl)methyl)thiophen-2-yl)-3-(chloromethyl)-5-methyl-4H-1,2,4-triazole (CAS 62551-57-9)
- Indometacin Impurity 37 (CAS CATO-C4X-147037)
- Dasatinib-d8 (CAS 1132093-70-9)
- Hydrocortisone Impurity 33 (CAS 77106-62-8)
- Lenvatinib Impurity 77 (CAS CATO-C4X-114077)
- Mianserin Impurity 103 (CAS 745757-89-5)
- (8-(3,4-Dimethoxyphenyl)-1,4-dioxaspiro[4.5]Decan-8-yl)methanamine (CAS 887978-91-8)
- 2-(4-Chlorophenyl)-6-methylpyrimidin-4(3H)-one (CAS 16858-20-1)
- 6-Bromo-4-methyl-2H-benzo[b][1,4]thiazin-3(4H)-one (CAS 1783455-40-2)
- (2-Fluoro-4-(trifluoromethyl)phenyl)methanol (CAS 197239-49-9)
- 2,3-Anhydro-4,6-O-benzylidene-N-(tert-butoxycarbonyl)-1,5-deoxy-1,5-imino-D-glucitol (CAS 133697-22-0)
- {4-fluorobicyclo[2.2.2]octan-1-yl}methanol (CAS 94994-16-8)
- Insulin Degludec Impurity 17 (CAS CATO-C4X-215717)
Why CATO?
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