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Nataša Djordjević Filijović Aleksandar Pavlović Ivan Vučković Katarina Nikolić Danica Agbaba 《Drug development and industrial pharmacy》2015,41(3):502-514
Stress stability testing represents an important part of the drug development process. It is used as an important tool for the identification of degradation products and degradation pathways, as well as for the assessment of changes in physical form of drug molecules. The impact of excipients on the stability of olanzapine confirms that levels of impurities and degradants are limiting parameters and are therefore used for stability evaluation. The major degradation product of olanzapine was identified as 2-methyl-5,10-dihydro-4H-thieno[2,3-b][1,5]benzodiazepine-4-one (III). The structure of III was determined by using LC-MS, IR and NMR. Compatibility and stress stability results demonstrated that tablet formulations of olanzapine are sensitive to temperature and moisture. In samples protected from moisture, the increase in concentration of III was shown to be highly temperature dependent and the degradation followed zero-order kinetics. In addition, studies of olanzapine with excipients and in formulated tablets revealed polymorphic phase changes in some samples, influenced by a combination of stress temperature and humidity conditions. Polymorphic transitions were monitored using x-ray powder diffraction (XRPD) analysis and exhibited no correlation between the phase change (appearance of a new polymorph) and the degradation process. 相似文献
23.
杂质对掺钕磷酸盐激光玻璃光谱性质的影响 总被引:1,自引:0,他引:1
综述了过渡金属杂质(Cu,Fe)和稀土杂质(Dy,Pr,Sm,Ce)对掺钕磷酸盐激光玻璃吸收损耗及Nd^3+荧光猝灭影响的研究状况。 相似文献
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气-质联机对嗪草酮原药及其主要杂质的分析 总被引:2,自引:0,他引:2
采用气桐色谱-质谱(GC—MS)联用对嗪草酮原药主成分及主要杂质进行分析,结合嗪草酮原药合成工艺,确定了3个主要杂质的结构和含量。同时利用杂质结构对嗪草酮的合成新方法进行验证。 相似文献
26.
为适应市场对成纱质量不断提高的要求,减少成纱结杂、粗节和提高条干水平,在技术改造中选用技术先进、质量好的器材,减少了半成品中的结杂和短绒,降低了条干CV值。实践表明,在梳棉上改变原固定盖板结构,选用新结构固定分梳板后,提了高纤维的分离度、伸直度和平行度,产品质量明显提高。 相似文献
27.
光电检测异纤清除机的原理和工艺性能 总被引:1,自引:1,他引:0
介绍了光电检测异纤清除机的组成和作用原理,分析了CCH高效自动分拣异纤机的主要工艺特性和最新发展,并结合工艺测试研究了影响检出率的主要因素,为异纤清除机的研制开发和应用提供参考。 相似文献
28.
亚麻、棉混纺纱纺制过程中,容易出现异性纤维、色差、布面麻粒多、橡皮纱、芝麻纱等质量问题。通过加大对原料的挑拣力度,在清梳并工序充分混合,设备上采取相应改进措施,选择合理的工艺及流程,加强运转管理,控制好各工序温湿度,能有效保证亚麻/棉混纺纱的质量稳定。 相似文献
29.
Daniel F Reyes David González Jose M Ulloa David L Sales Lara Dominguez Alvaro Mayoral Adrian Hierro 《Nanoscale research letters》2012,7(1):653
The use of GaAsSbN capping layers on InAs/GaAs quantum dots (QDs) has recently been proposed for micro- and optoelectronic applications for their ability to independently tailor electron and hole confinement potentials. However, there is a lack of knowledge about the structural and compositional changes associated with the process of simultaneous Sb and N incorporation. In the present work, we have characterized using transmission electron microscopy techniques the effects of adding N in the GaAsSb/InAs/GaAs QD system. Firstly, strain maps of the regions away from the InAs QDs had revealed a huge reduction of the strain fields with the N incorporation but a higher inhomogeneity, which points to a composition modulation enhancement with the presence of Sb-rich and Sb-poor regions in the range of a few nanometers. On the other hand, the average strain in the QDs and surroundings is also similar in both cases. It could be explained by the accumulation of Sb above the QDs, compensating the tensile strain induced by the N incorporation together with an In-Ga intermixing inhibition. Indeed, compositional maps of column resolution from aberration-corrected Z-contrast images confirmed that the addition of N enhances the preferential deposition of Sb above the InAs QD, giving rise to an undulation of the growth front. As an outcome, the strong redshift in the photoluminescence spectrum of the GaAsSbN sample cannot be attributed only to the N-related reduction of the conduction band offset but also to an enhancement of the effect of Sb on the QD band structure. 相似文献
30.
《分离科学与技术》2012,47(4):874-893
Abstract Atmospheric air contains various trace impurities which include oxides of nitrogen, carbon, sulphur, and light hydrocarbons. Prior to cryogenic distillation of air to produce oxygen, nitrogen, and argon, these trace impurities have to be removed since many of these compounds constitute a safety hazard in the plant. In this study, adsorption has been considered for their removal and adsorption behavior of ethylene, acetylene, nitrous oxide, acetonitrile, methyl tert-butyl ether, methyl sulfoxide, dimethyl sulfoxide, and methanol have been studied in the Henry's Law low concentration region with several different adsorbents. Adsorption equilibrium parameters have been determined with samples of Alcan pure alumina, Alcan alumina/13X composites Actiguard 600/650PC, CABSORB Chabazite, Ceca13X, and Clinoptilolite by using the concentration pulse chromatographic technique. Heat of adsorption values and van't Hoff plots have been presented. 相似文献