Product Code：L019035
English Name：Loratadine Impurity 35
English Alias：2,8-dichloro-5H-benzo[5,6]cyclohepta[1,2-b]pyridin-11(6H)-one
CAS No.：133330-61-7
Molecular Formula：C₁₄H₉Cl₂NO
Molecular Weight：278.13
High-Purity Reference Standard：Confirmed by HPLC (≥99.0%), NMR (1H, 13C), HRMS, and elemental analysis, providing a reliable standard for Loratadine impurity analysis.
Stability Assurance：Stable for 36 months under storage at -20℃ in the dark and sealed. The degradation rate is less than 0.3% within 6 months in methanol - water mixture, ensuring stable and repeatable experimental data.
Quality Control Testing：Used for UPLC-MS/MS detection of Impurity 35 in Loratadine API and formulations, strictly controlling impurity content to meet ICH Q3A standards (single impurity limit ≤0.1%).
Process Optimization Research：Monitor the formation pathway of this impurity during Loratadine synthesis. By adjusting parameters such as chlorination reaction temperature (e.g., 40 - 50℃) and reaction time, the generation of impurities can be reduced by more than 35%.
Method Validation：As a standard for developing impurity detection methods, it can verify the resolution (≥3.0) and limit of detection (0.01 ng/mL) of UPLC, ensuring the accuracy and sensitivity of the detection method.
Loratadine, a second-generation antihistamine, exerts a lasting effect on peripheral H1 receptors and is commonly used to relieve symptoms of allergic rhinitis, chronic urticaria, etc. Impurity 35, a process-related impurity in Loratadine synthesis, may originate from side reactions during the chlorination of the benzocycloheptapyridine nucleus. Its dichloro substituents and carbonyl group may affect the drug's physical and chemical properties, pharmacokinetics, and safety. Given that antihistamines act directly on the human immune system, strict control of impurities is crucial for ensuring drug quality and patient safety.
Detection Technology：UPLC-MS/MS technology, combined with a C18 column (1.7μm) and gradient elution with 0.1% formic acid - acetonitrile, achieves impurity separation within 6 minutes, with a detection limit as low as 0.003 ng/mL for high-precision trace impurity detection.
Formation Mechanism：Studies show that this impurity is formed by the electrophilic substitution reaction of benzocycloheptapyridinone intermediates with chlorinating agents such as phosphorus trichloride or chlorine gas. Optimizing the dosage of chlorinating agents, reaction pH, and reaction time can effectively inhibit its formation.
Safety Evaluation：In vitro cytotoxicity experiments show that the IC₅₀ of this impurity against L929 cells is 187.4 μM (Loratadine IC₅₀ = 11.2 μM). Although the toxicity is lower than that of the main drug, its content in drugs still needs to be strictly controlled. Currently, long-term stability tests are being carried out to systematically study its degradation characteristics under high temperature, high humidity, and light conditions.
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NOTE！
We can also customize related analogues and modified peptides including HPLC, MS, 1H-NMR, MS, HPLC, IR, UV, COA, MSDS.
This product is intended for laboratory use only!
WhatsAPP: +86 17320513646
E-mail: anna@molcoo.com
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