The objective of current study was to develop a validated specific stability indicating reversed-phase liquid chromatographic method for the quantitative determination of desvenlafaxine in bulk sample and pharmaceutic...The objective of current study was to develop a validated specific stability indicating reversed-phase liquid chromatographic method for the quantitative determination of desvenlafaxine in bulk sample and pharmaceutical dosage form in the presence of degradation products. Forced degradation studies were performed on bulk sample of desvenlafaxine as per ICH prescribed stress conditions using acid, base, oxidative and photolytic degradation to show the stability indicating power of the method. Significant degradation was observed under acidic stress condition and the degradation product formed was identified by LC-MS and a degradation pathway for drug has been proposed. Successful separation of drug from degradation products formed under stress conditions was achieved on a SymmetryShield column C 18 (5 mm, 250 mm 4.6 mm, i.d.) using the mobile phase consisting of a mixture of 0.2% (v/v) triethylamine in ammonium acetate (0.05 M; pH 6.5) and methanol using isocratic gradient.展开更多
An aqueous solution of the extracts from Rhododendron leaves from Sichuan Liangshan was extracted with solvents of increasing polarity, petroleum ether, ethyl ether, ethyl acetate and butanol. The main flavonoid aglyc...An aqueous solution of the extracts from Rhododendron leaves from Sichuan Liangshan was extracted with solvents of increasing polarity, petroleum ether, ethyl ether, ethyl acetate and butanol. The main flavonoid aglycons extracted into the ethyl ether phase are the subject of this study. The flavonoid aglycons—mycetin, quercetin, kaempferol and farrerol, were separated and identified by thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometer/mass spectrometer (LC/MS/MS). A simple and rapid HPLC method was developed for quantitative determination of quercetin and kaempferol in Rhododendron leaves, ethanol extracts and Jinjuan oral liquid drug (Liquor Jinjuan). The analysis of quercetin is useful for quality control of medicinal materials and Liquor Jinjuan products.展开更多
文摘The objective of current study was to develop a validated specific stability indicating reversed-phase liquid chromatographic method for the quantitative determination of desvenlafaxine in bulk sample and pharmaceutical dosage form in the presence of degradation products. Forced degradation studies were performed on bulk sample of desvenlafaxine as per ICH prescribed stress conditions using acid, base, oxidative and photolytic degradation to show the stability indicating power of the method. Significant degradation was observed under acidic stress condition and the degradation product formed was identified by LC-MS and a degradation pathway for drug has been proposed. Successful separation of drug from degradation products formed under stress conditions was achieved on a SymmetryShield column C 18 (5 mm, 250 mm 4.6 mm, i.d.) using the mobile phase consisting of a mixture of 0.2% (v/v) triethylamine in ammonium acetate (0.05 M; pH 6.5) and methanol using isocratic gradient.
文摘An aqueous solution of the extracts from Rhododendron leaves from Sichuan Liangshan was extracted with solvents of increasing polarity, petroleum ether, ethyl ether, ethyl acetate and butanol. The main flavonoid aglycons extracted into the ethyl ether phase are the subject of this study. The flavonoid aglycons—mycetin, quercetin, kaempferol and farrerol, were separated and identified by thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometer/mass spectrometer (LC/MS/MS). A simple and rapid HPLC method was developed for quantitative determination of quercetin and kaempferol in Rhododendron leaves, ethanol extracts and Jinjuan oral liquid drug (Liquor Jinjuan). The analysis of quercetin is useful for quality control of medicinal materials and Liquor Jinjuan products.
