The development and implementation of advanced analytical technologies is essential for extending the expiry for complex drug products stored in the Strategic National Stockpiles. Consequently, a novel Ultra High-Perf...The development and implementation of advanced analytical technologies is essential for extending the expiry for complex drug products stored in the Strategic National Stockpiles. Consequently, a novel Ultra High-Performance Liquid Chromatographic (UHPLC) method has been developed for the analysis of atropine and its respective impurities to support the analytical research platform for auto-injectors. This study is part of a larger research effort to improve the efficiency and broaden the applicability of advanced analytical methods for medical counter-measure medications. The current HPLC compendial methodology for atropine sulfate injection requires an analysis time of 40 minutes for atropine. In comparison, the novel gradient UHPLC method required only 8 minutes to evaluate both atropine and its major pharmaceutical impurities. Improved separation was achieved on a Waters Acquity UHPLC BEH C18 1.7 μm, 2.1 × 100 mm column employing gradient elution of mobile phase solvent A (0.1% H3PO4) and solvent B (0.1% H3PO4, 90% ACN, and 10% H2O). The method was validated according to USP Category I requirements for assay. The daily standard calibration curves were linear over a concentration range from 50 μg/mL to 250 μg/mL with a correlation coefficient of >0.999. The detection limit (LOD) and quantitation limit (LOQ) were 3.9 μg/ml and 13.1 μg/ml, respectively. Resolution results indicate that atropine and the following impurities, degradants and a preservative can also be separated and analyzed using this proposed method: noratropine, 4,4’-di-hy-droxydiphenyl ether, 2,4’-dihydroxydiphenyl ether, 4-bromophenol, 4-hydro-xyatropine, tropic acid, apoatropine HCl, atropic acid, hydroquinone, nitroethane, phenol and catechol. The UHPLC method demonstrated enhanced selectivity and significantly reduced the analysis time when compared with the traditional USP compendial HPLC method. The method was successfully applied to the evaluation of atropine in ATNAA auto-injectors lots from the Strategic National Stockpiles.展开更多
The Mg-based hydrogen storage alloys Mg2Ni, Mg2Ni0.7Fe0.3 and Mgl.7Alo.3Ni were successfully synthesized by a two-step process （sintering and ball milling）. The crystal structure and microstructure were examined by ...The Mg-based hydrogen storage alloys Mg2Ni, Mg2Ni0.7Fe0.3 and Mgl.7Alo.3Ni were successfully synthesized by a two-step process （sintering and ball milling）. The crystal structure and microstructure were examined by X-ray diffraction, Scanning Electron Microscope and Malvern particle size analyzer. New phase appears in the tripe alloys doped with A1 and Fe, and the particle size ranges from 3μm to 5 μm. The electrochemical performance studies indicate that the partial substitution of AI for Mg, and Fe for Ni significantly improve the cycle life, reversibility of hydrogen absorption and desorption. The diffusion process is the control step in the electrode reaction of hydrogen storage alloys.展开更多
文摘The development and implementation of advanced analytical technologies is essential for extending the expiry for complex drug products stored in the Strategic National Stockpiles. Consequently, a novel Ultra High-Performance Liquid Chromatographic (UHPLC) method has been developed for the analysis of atropine and its respective impurities to support the analytical research platform for auto-injectors. This study is part of a larger research effort to improve the efficiency and broaden the applicability of advanced analytical methods for medical counter-measure medications. The current HPLC compendial methodology for atropine sulfate injection requires an analysis time of 40 minutes for atropine. In comparison, the novel gradient UHPLC method required only 8 minutes to evaluate both atropine and its major pharmaceutical impurities. Improved separation was achieved on a Waters Acquity UHPLC BEH C18 1.7 μm, 2.1 × 100 mm column employing gradient elution of mobile phase solvent A (0.1% H3PO4) and solvent B (0.1% H3PO4, 90% ACN, and 10% H2O). The method was validated according to USP Category I requirements for assay. The daily standard calibration curves were linear over a concentration range from 50 μg/mL to 250 μg/mL with a correlation coefficient of >0.999. The detection limit (LOD) and quantitation limit (LOQ) were 3.9 μg/ml and 13.1 μg/ml, respectively. Resolution results indicate that atropine and the following impurities, degradants and a preservative can also be separated and analyzed using this proposed method: noratropine, 4,4’-di-hy-droxydiphenyl ether, 2,4’-dihydroxydiphenyl ether, 4-bromophenol, 4-hydro-xyatropine, tropic acid, apoatropine HCl, atropic acid, hydroquinone, nitroethane, phenol and catechol. The UHPLC method demonstrated enhanced selectivity and significantly reduced the analysis time when compared with the traditional USP compendial HPLC method. The method was successfully applied to the evaluation of atropine in ATNAA auto-injectors lots from the Strategic National Stockpiles.
基金Funded by the National High Technology Research and Development Program of China (Key Project) (2001AA 331050) and the Chongqing Applied Fundamental Research (7941-2).
文摘The Mg-based hydrogen storage alloys Mg2Ni, Mg2Ni0.7Fe0.3 and Mgl.7Alo.3Ni were successfully synthesized by a two-step process （sintering and ball milling）. The crystal structure and microstructure were examined by X-ray diffraction, Scanning Electron Microscope and Malvern particle size analyzer. New phase appears in the tripe alloys doped with A1 and Fe, and the particle size ranges from 3μm to 5 μm. The electrochemical performance studies indicate that the partial substitution of AI for Mg, and Fe for Ni significantly improve the cycle life, reversibility of hydrogen absorption and desorption. The diffusion process is the control step in the electrode reaction of hydrogen storage alloys.
