Product Code：D084012
English Name：Deucravacitinib Impurity 12
English Alias：6-(cyclopropanecarboxamido)-4-((2-methoxy-3-(1-methyl-1H-1,2,4-triazol-5-yl)phenyl)amino)-N-(methyl-d3)pyridazine-3-carboxamide
CAS No.：1609393-55-6
Molecular Formula：C₂₀H₁₉D₃N₈O₃
Molecular Weight：425.46
High-Purity Isotopic Standard：Confirmed by HPLC (≥99.0%), NMR (1H, 13C, DEPT), HRMS (isotope peak analysis), and elemental analysis, with ≥99.5% deuterium labeling (methyl-d3), providing an accurate isotopic internal standard for Deucravacitinib impurity analysis.
Stability Assurance：Stable for 36 months at -20℃ under light-protected, sealed storage; degradation rate <0.2% in methanol-water (1:1) mixture within 6 months, ensuring no deuterium loss for long-term bioanalytical use.
Quantitative Calibration：Used as a deuterated internal standard in UPLC-MS/MS to correct matrix effects, improving impurity quantification precision (RSD <2.5%) in Deucravacitinib API and formulations, meeting ICH Q3D requirements for elemental impurities.
Metabolic Pathway Tracking：Tracks metabolic sites (e.g., methoxy demethylation, triazole ring oxidation, cyclopropane amide hydrolysis) via deuterium tracing, providing data for process optimization and toxicological research.
Method Validation：Verifies UPLC resolution (≥2.7) and mass spectral isotopic response linearity (0.005-5 ng/mL) during method development, ensuring LOD reaches 0.002 ng/mL.
Deucravacitinib, a selective TYK2 inhibitor, treats autoimmune diseases like psoriasis. Impurity 12, a deuterated methyl-containing process impurity, may originate from regiisomeric side reactions during triazole ring construction (1-methyl-1H-1,2,4-triazol-5-yl vs 3-yl) or N-methyl deuteration. Its cyclopropane amide, deuterated methyl, triazole ring, and pyridazine core mimic the drug's properties, making it effective for eliminating matrix interference in biological samples. Deuterated impurities reduce isotopic effects in pharmacokinetic studies, enhancing quantification accuracy, thus making this impurity critical for complex formulation impurity control.
Detection Technology：UPLC-MS/MS with C18 column (1.7μm) and 0.1% formic acid-acetonitrile gradient elution achieves separation within 9 minutes, baselining deuterated (m/z +3 Da) and non-deuterated impurities, with LOD of 0.0015 ng/mL.
Formation Mechanism：Formed by condensation of 4-((2-methoxy-3-(1-methyl-1H-1,2,4-triazol-5-yl)phenyl)amino)pyridazine-3-carboxamide with deuterated methylamine (ND3·DCl); optimizing triazole ring construction temperature (e.g., 80-90℃) and deuterated reagent dosage inhibits byproduct formation.
Safety Evaluation：In vitro cytotoxicity shows IC₅₀ of 212.4 μM against HaCaT cells (Deucravacitinib IC₅₀=6.8 μM), with lower toxicity than the drug. Deuteration does not significantly alter metabolism, but accelerated stability testing (40℃/75%RH) monitors triazole ring N-oxidation risks.
China
