RESUMO
Six impurities in pantoprazole sodium bulk drug substance were detected by a simple high performance liquid chromatographic method (HPLC) whose area percentage ranged from approximately 0.05 to 0.34%. Liquid chromatography-mass spectrometry (LC-MS) was performed to identify the molecular weight of the impurities. A thorough study was undertaken to characterize these impurities. These impurities were synthesized, subsequently characterized and were co-injected with the sample containing impurities and found the retention time match of the spiked impurities. Based on their spectral data (IR, NMR and MS), these impurities were characterized as; 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-2-pyridinyl)methyl]thio]-1H-benzimidazole (Impurity-I); 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-2-pyridinyl)methyl]sulfonyl]-1H-benzimidazole (Impurity-II); 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-1-oxide-2-pyridinyl)methyl]sulfonyl]-1H-benzimidazole (Impurity-III); 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-2-pyridinyl)methyl]thio]-1-((3,4-dimethoxy-2-pyridinyl)methyl)-1H-benzimidazole (Impurity-IV); 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-2-pyridinyl)methyl]sulfinyl]-1-((3,4-dimethoxy-2-pyridinyl)methyl)-1H-benzimidazole (Impurity-V); 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-1-oxide-2-pyridinyl)methyl]sulfinyl]-1H-benzimidazole (Impurity-VI). The formation of these impurities was proposed. The structure of the Impurity-II was unambiguously confirmed by single crystal X-ray diffraction (XRD) studies.
Assuntos
2-Piridinilmetilsulfinilbenzimidazóis/análise , Antiulcerosos/análise , 2-Piridinilmetilsulfinilbenzimidazóis/química , Antiulcerosos/química , Cromatografia Líquida , Contaminação de Medicamentos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular , Peso Molecular , Pantoprazol , Espectrofotometria Infravermelho , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios XRESUMO
Six impurities in rabeprazole sodium bulk drug substance were detected by a simple isocratic high performance chromatographic method (HPLC) whose area percentage ranged from 0.60 to 1.46%. LC-MS was performed to identify the mass of the impurities. A thorough study was undertaken to characterize these impurities. These impurities were synthesized, subsequently characterized and were co-injected with the sample containing impurities and are found to be matching with the impurities in the sample. Based on their spectral data (IR, NMR and MS), these impurities were characterized as 2-[[[4-(3-methoxypropoxy)-3-methyl-2-pyridinyl] methyl]thio]-1H-benzimidazole (impurity I); 2-[[[4-(3-methoxypropoxy)-3-methyl-2-pyridinyl] methyl] sulfonyl]-1H-benzimidazole (impurity II); 2-[[[4-(3-methoxypropoxy)-3-methyl-2-pyridinyl-1-oxide] methyl] sulfonyl]-1H-benzimidazole (impurity III); 2-[[[4-(3-methoxypropoxy)-3-methyl] pyridin-2-yl]methanesulfinyl]-1-[[4-(3-methoxypropoxy)-3-methyl]pyridin-2-ylmethyl]-1H-benzimidazole (impurity IV); 2-[[[4-methoxy-3-methyl-2-pyridinyl] methyl] sulfinyl]-1H-benzimidazole (impurity V); 2-[[[4-(3-methoxypropoxy)-3-methyl-2-pyridine-1-oxide] methyl] sulfinyl]-1H-benzimidazole (impurity VI).
