Gas-Liquid Chromatographic Determination of Pipemidic Acid

A gas chromatographic method was established for the quantitative analysis of pipemidic acid. The method is based on alkylation of pipemidic acid with diazomethane catalyzed by boron trifluoride. The sample was chromatographed on a stainless steel column packed with 5% OV-101 on Chromosorb G-HP and n-octacosane was used as an internal standard. Quantitation is achieved by measuring peak-height ratio. The method was satisfactorily applied to the analysis of pipemidic acid in tablet.     

Total monitoring of the constituents of Danshen tablet using micellar electrokinetic chromatography fingerprinting for antioxidant activity profiling

A micellar electrokinetic chromatography fingerprint coupled with quantification was developed for assessing the quality consistency of Danshen tablets, a traditional Chinese medicine, with pharmacological activities of activating blood to remove blood stasis and regulating the flow of vital energy to alleviate pain. Square optimization method was proposed to select the suitable background electrolyte. Subsequently, the index of chromatographic fingerprints F was simultaneously employed as an objective function to evaluate capillary electrophoresis conditions. After that, the method was proved to meet the fingerprint analysis criteria by evaluating stability, linearity, limit of detection, limit of quantification, precision, accuracy, and repeatability. Moreover, systematic quantified fingerprint method was used to evaluate chromatographic fingerprints of 30 batches of samples in terms of both quality and quantitation. The result indicated that the chemical compositions of samples were basically similar while their contents showed marked variation. In addition, the fingerprint–efficacy relationship was established using partial least squares model, which can serve as anti‐oxidant activity evaluation of Danshen tablets as well as a reference for the selection of active constituents. The proposed method can be applied for the holistic quality control of Danshen tablets.     

微流控芯片非接触电导法快速测定盐酸美金刚片中盐酸美金刚的含量

建立了微流控芯片非接触电导法快速测定盐酸美金刚片中盐酸美金刚含量的方法。探讨了缓冲溶液的种类、浓度、pH值、进样时间及分离电压等因素对分离检测的影响。优化得到缓冲体系为含2%(体积分数)二甲基亚砜(DMSO)的3.0 mmol/L三乙胺-2.0 mmol/L磷酸缓冲溶液(pH 3.3),进样时间为10 s,分离电压为2.0 kV。优化条件下,盐酸美金刚的线性范围为10～2 000μg/mL(r~2=0.999 1);检出限为7μg/mL,定量下限为10μg/mL;精密度、稳定性、重复性实验的相对标准偏差(RSD)均小于2.0%;平均加标回收率为96.5%～99.2%;盐酸美金刚的检测时间小于18 s。该方法快速简便,适用于盐酸美金刚片中盐酸美金刚含量的测定。     

Determination of Candesartan Cilexetil in Tablet Dosage Forms and Dissolution Testing Samples by First Derivative UV Spectrophotometric Method

Abstract

This article describes the development and validation of a first derivative UV quantitative analytical method for determination of candesartan cilexetil in tablet dosage forms. A signal at 270.1 nm of the first derivative spectrum (ID_270.1) was found adequate for quantification. The limit of quantification was 3.06 µg/ml. The linearity between ID_270.1 nm and concentration of candesartan cilexetil in the range of 6.00–32.00 µg/ml presented a correlation coefficient of (r²) = 0.9990. The mean recovery percentage was 100.97 and 99.23% for candesartan cilexetil standard solution and candesartan standard cilexetil solution with excipients, respectively. The intraday and interday accuracy of the assay was 98.60% and 99.10% respectively. The intraday and interday variability was below 2.0%.

The proposed method is accurate, precise, sensitive, and selective and can be used in quality control laboratories for its intended purpose.     

Mathematics instruction and the tablet PC

The use of tablet PCs in teaching is a relatively new phenomenon. A cross between a notebook computer and a personal digital assistant (PDA), the tablet PC has all of the features of a notebook with the additional capability that the screen can also be used for input. Tablet PCs are usually equipped with a stylus that allows the user to write on the screen. Handwriting recognition software converts this input into text for use with software such as internet browsers and email programs. As an educational tool, two of the most important features of the tablet PC are annotation and wireless communication. The annotation feature allows the user to write on almost any document much as one would annotate a printout of the same document. The wireless communication feature allows tablet PCs to share information with one another. The advantages of these features and their impact on the Murray State University (MSU) classroom will be discussed in the evaluation section.     

普伐他汀钠片的溶出曲线研究

以普伐他汀钠片溶出曲线研究为例,详解溶出度实验和方法建立的一般过程和要求,有助于学生加强对固体口服制剂溶出度实验的理解并形成初步的研究思路,有利于培养适应制药工业发展需求的应用型人才。     

基于挥发性组分的气相色谱指纹图谱评价沉香化气片质量

建立了沉香化气片的气相色谱指纹图谱,并结合化学模式识别评价20批沉香化气片的质量。乙醇超声提取20批沉香化气片的挥发性成分,以正十八烷为内标,分析了3个主要组分的含量,且以内标计算其他各组分的相对峰面积,建立了沉香化气片的气相色谱指纹图谱,确定了11个共有峰,得到了各批次样品的相似度,并通过气相色谱-质谱法和对照品比对对10个共有峰进行了指认。将获得的峰面积指纹图谱采用系统聚类分析和主成分分析进行化学模式识别研究,实现了不同批次沉香化气片的区分,发现了造成不同批次样品差异的主要标记物。该方法有效且综合性强,为科学评价与有效控制沉香化气片的质量提供了可靠的参考。     

粉末压片X射线荧光光谱法测定铌铁合金中 铁、铌、硅、铝、磷

为提高铌铁合金检验效率,替代繁琐的化学湿法分析,采用粉末压片制样,利用X荧光光谱法对铌铁合金中Fe、Nb、Si、Al、P 5种主要成分进行测定。选用定值过的生产样品作为内控标准样品,主要研究制样细节对分析结果的影响,确认合适的试样粒度和压片参数,通过曲线拟合建立校准曲线。测定结果与化学湿法和电感耦合等离子体原子发射光谱法测定结果比较,各组分精密度相对标准偏差为0.48%～1.9%,准确度满足国标分析要求。     

ICA方法与NIR技术用于药片中活性成分含量的测定

用独立分量分析(ICA)方法提取药片近红外光谱数据矩阵的独立成分和相应的混合矩阵, 再用BP神经网络对混合矩阵和药片中活性成分的浓度矩阵进行建模, 提出了新的药片活性成分含量测定的基于独立分量分析-神经网络回归(ICA-NNR)的近红外光谱分析方法. 通过分析独立分量数和网络中间隐层的神经元数对模型性能的影响, 分别建立三类药片定量分析的最优模型. 该方法用于实测的三类药片中活性成分含量的测定, 测试样品集的化学检测值与近红外预测值的相关系数分别达到0.962, 0.980及0.979. 结果表明, 基于ICA-NNR的近红外光谱分析方法对制药业的药片进行定量分析是可行的.