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151.
152.
铁(Ⅲ)置换氧化还原滴定法测定维生素C片剂及针剂中抗坏血酸 总被引:1,自引:0,他引:1
基于将测定抗坏血酸的碘滴定(药典)法和铁铵矾滴定法相结合,即先用铁铵矾基准物氧化碘化钾置换出相当量的12,再在维生素C药物溶液滴定中让相当量的12定量氧化抗坏血酸。合适的反应条件是:乙酸介质,碘离子过量,室温置暗处置换反应10min。将该法用于维生素C药物中抗坏血酸的测定,结果与药典法结果相符。 相似文献
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154.
采用漫反射傅里叶变换红外光谱法(DRIFTS)测定维生素C制剂中抗坏血酸的含量。选择合适的分析峰1660~1680 cm–1,可排除其它成分的影响,吸光度与抗坏血酸的浓度呈良好线性关系。以镜面为背景,以75μm筛过筛后的KBr为稀释剂,用DRIFTS法分别测定了3种市售维生素C制剂中的抗坏血酸含量,测定结果分别为75.60%,9.80%,6.72%;相对标准偏差(n=6)分别为6.6%,4.9%,8.2%,与碘量法测定结果接近。样品加标回收率为94.0%。DRIFTS法测定维生素C中的抗坏血酸方法简便、准确,无试剂消耗,无废液产生,是非破坏和非污染的绿色分析方法。但其测定结果的精密度不如碘量法,而且其测定结果的准确程度受样品的性状限制,对于白色粉末或可研磨为粉末的样品分析结果准确度较高。 相似文献
155.
Simultaneous determination of notoginsenoside R1 and ginsenoside Re in rat plasma by ultra high performance liquid chromatography with tandem mass spectrometry and its application to a pharmacokinetic study 下载免费PDF全文
Lijing Zhu Qian Zhang Yang Zong Shijia Liu Changyin Li Wenzheng Ju 《Journal of separation science》2016,39(17):3368-3374
A rapid and high sensitive ultra high performance liquid chromatography with tandem mass spectrometry method for the simultaneous determination of notoginsenoside R1 and ginsenoside Re in rat plasma was developed. The analytes and internal standard, digoxin, were extracted from rat plasma via protein precipitation with methanol and separated on an Phenomenex Gemini C18 column within 2 min. Quantitation was performed on a triple quadrupole mass spectrometer employing electrospray ionization technique, operating in multiple reaction monitoring and positive ion mode. The precursor to product ion transitions monitored for notoginsenoside R1, ginsenoside Re, and internal standard were m/z 955.5→775.5, 969.6→789.1, and 803.6→283.1, respectively. The assay was validated with linear range of 1.9–380 ng/mL for notoginsenoside R1 and 0.5–100 ng/mL for ginsenoside Re. The intra‐ and interday precisions (RSD%) were within 8.96% for each analyte. The absolute recoveries were greater than 93% for R1 and 96% for Re. Each analyte was stable during all sample storage, preparation, and analytic procedures. The method was successfully applied to a pharmacokinetic study of Xuesaitong dispersible tablets in eight rats. 相似文献
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毛细管电泳测定双氯芬酸钠制剂中的双氯芬酸钠 总被引:2,自引:0,他引:2
建立了制剂中双氯芬酸钠毛细管电泳高频电导分析法,并用于氯芬黄敏片及双氯芬酸钠肠溶片中双氯芬酸钠的测定。对电泳介质的种类、浓度以及操作电压和进样量等影响因素进行了优化。实验采用5mmol/L乳酸为缓冲溶液,22.0kV为分离电压,可在9min内实现对双氯芬酸钠的分离检测。在最佳实验条件下,双氯芬酸钠的线性范围为0.4~100μg/mL,检出限为0.1μg/mL。成功地检测了氯芬黄敏片及双氯芬酸钠肠溶片的有效成分双氯芬酸钠,回收率为92.4%~103.0%。 相似文献
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利用近红外光谱结合偏最小二乘法实现对不同品牌盐酸左西替利嗪片剂有效成分的定量分析。经内部交叉验证,确定最佳波数范围和光谱预处理方法,以及最佳主成分数,建立最优PLS校正模型。对验证集样品浓度进行预测,得到均方根误差RMSECV、决定系数R2分别为0.276和0.974。该方法能够用于不同厂家盐酸左西替利嗪片的快速定量分析,是一种有效的药品快速检验技术。 相似文献
160.
The incidence of compression conditions, porosity and polymer degradation on human growth hormone (hGH) release from PLGA implantable tablets was evaluated with the aim of gaining insight in the mechanism involved in drug delivery from biodegradable matrices. Tablets elaborated by direct compression of hGH with PLGA, applying various compression forces for different times, kept the integrity and the stability of the hormone. Tablet dimensions, viscoelastic properties, glass to rubber transition temperature (Tg), PLGA degradation rate and water uptake were analyzed in the freshly prepared implantable tablets as well as at several times during release test in phosphate buffer pH 7.4. Placebo tablets were also prepared to evaluate the incidence of hGH on the physicomechanical properties of the device and PLGA degradation rate. Porosity remarkably determined the amount of hGH released, through an effect on the easiness of water penetration in the tablet and on the beginning of PLGA degradation. The decrease in PLGA molecular weight during the first days in the release medium, despite of being minor, significantly conditioned hGH release rate. The more dramatic changes in PLGA molecular weight observed after 20 days in the release medium notably reduced the Tg and the viscous and elastic moduli of the tablets. The overall analysis of the events underwent by the tablets in contact with the aqueous medium was used to explain the drug release profile and may help to optimize the design of the PLGA-based implantable tablets as peptidic drug delivery systems. 相似文献