Investigating the Effects of Excipients on the Powder Flow Characteristics of Theophylline Anhydrous Powder Formulations

Abstract

Pharmaceutical excipients may have a great effect on properties affecting tablet production. To determine if formulations containing theophylline anhydrous would have properties allowing them to be easily tableted, functional parameters affecting powder flow were evaluated. The Carr Flowability Indices were used for this evaluation. Formulations to be studied include theophylline anhydrous as the active ingredient, hydrous lactose and dicalcium phosphate dihydrate as diluents, polyvinylpyrrolidone as a binder, and fumed silica as a flow promoter. The effect of each component on powder flow is discussed.     

物体变形测量的相移数字散斑剪切干涉术

相移数字散斑剪切干涉技术可以提高检测精度,利用该方法对圆形铝板试件进行测量。为了实现全场相位的精确求解,运用等四步相移Carré算法定量计算相位。将该非接触测量技术与弹性力学理论分析相结合,对四周固支,中心受集中载荷试件的离面位移导数进行测量与分析,另外采用有限元方法进行模拟。最后将实验结果分别和理论结果、有限元结果进...     

氧化胁迫对毛白杨叶肉细胞结构和生理功能的影响

为了研究氧化胁迫条件下,毛白杨植株细胞结构和生理生化的变化特征,从而为木本植物应对氧化胁迫的研究提供实验依据.本研究以毛白杨组培植株为实验材料,利用过氧化氢溶液浸泡处理离体叶片进行氧化胁迫,测量氧化胁迫前后各项生理指标的变化并观察细胞结构形态的变化.结果表明氧化胁迫后,毛白杨植株内过氧化氢含量明显升高;伴随着NADP+/NADPH比值的显著升高,抗坏血酸的含量明显下降;同时丙二醛含量明显升高;ADP/ATP比值明显下降;蛋白羰基化程度随过氧化氢含量的升高而增强;叶肉细胞及叶绿体结构发生改变,叶绿体双层膜结构不清晰,类囊体片层结构解体.结论:毛白杨受到氧化胁迫后体内活性氧含量迅速升高,造成膜脂、蛋白质及细胞结构受到不同程度的氧化损伤.     

小麦种类及加工方式对全麦粉粉体特性的影响

为了研究全麦粉粉体特性,以卡尔指数原理为理论基础,使用粉体综合特性测试仪,对红麦、白麦、加麦3种不同种类的小麦面粉及不同加工方式下全麦粉粉体的特性,包括Carr流动性综合指数Fw和喷流性综合指数Fd,及其单项检测项目等进行逐一对比分析。结果表明,不同种类小麦的面粉及全麦粉的流动性呈显著性差异,面粉与全麦粉流动性呈极显著的差异性(p<0.01),但不同加工方式的全麦粉流动性没有显著性差异;面粉及全麦粉的流动性状均表现不太好,面粉有相当强的喷流性,但全麦粉仅表现出有倾向的喷流性状。     

食品粉体颗粒流动性分形维测试法

食品粉体颗粒粒度分布分形维能很好的表征颗粒群粒度分布。本文通过建立适合于数字显微方法测定粉体颗粒粒度分布分形维数值的数学模型,探讨食品粉体流动参数与颗粒粒度分布分形维数值间的关系。结果表明:食品粉体颗粒粒度分布分形维数值可以用于表征食品粉体流动性,各流动性表征参数与粒度分布分形维数值间具有明显的相关关系。因此,可以采用粒度分布分形维数值作为食品粉体流动性能的评价指标。形成了可靠、简洁的食品粉体流动性能测试新方法。     

Investigating the effects of excipients on the powder flow characteristics of theophylline anhydrous powder formulations

Pharmaceutical excipients may have a great effect on properties affecting tablet production. To determine if formulations containing theophylline anhydrous would have properties allowing them to be easily tableted, functional parameters affecting powder flow were evaluated. The Carr Flowability Indices were used for this evaluation. Formulations to be studied include theophylline anhydrous as the active ingredient, hydrous lactose and dicalcium phosphate dihydrate as diluents, polyvinylpyrrolidone as a binder, and fumed silica as a flow promoter. The effect of each component on powder flow is discussed.     

A quantitative feeding bioassay forPissodes strobi Peck (Coleoptera: Curculionidae)

A feeding bioassay forPissodes strobi Peck was developed that consisted of plastic petri dishes containing paired agar disks immersed in paraffin wax. Lens paper covering the top surface of the disks provided 1, 2, or 3 weevils in each replicate with a surface through which they made regular feeding punctures which could be easily counted. The number of feeding punctures was correlated with the amount of agar ingested. Candidate feeding stimulants or deterrents were applied to the paper covering one of the disks in the dishes, while the other served as a solvent control. Feeding stimulants were tested using disks of pure agar, and deterrents were assayed on agar disks that contained 2% ground, dried Sitka spruce bark,Picea sitchensis Carr. The weevils exhibited a concentration-dependent response to the amount of spruce bark in the agar disk. Feeding stimulation by Sitka spruce bark extracts, and deterrency by leaf oil of western red cedar,Thuja plicata Donn, was demonstrated. The bioassay would be useful in chemical isolation programs aimed at identification of feeding stimulants and deterrents.Research supported by National Research Council of Canada Cooperative Grant A0243 and Operating Grants A3881 and A3706.     

强化面粉用营养素强化剂单体流动性与喷流性评价

为探讨通用强化面粉配方中所涉及营养素单体粉体的流动性与喷流性,采用粉体综合特性测试仪对样品的休止角、崩溃角、差角、平板角、松装密度、振实密度、压缩度、均齐度、分散度等物性指标进行测试计算,参照Carr流动性与喷流性指数表计算出样品的流动性指数及喷流性指数。结果表明：各营养素单体流动性指数最低38、最高90.5,喷流性指数最低35.5、最高67.5,各营养素单体在流动性能与喷流性能上存在较为明显的差异。休止角、压缩度、平板角与流动性指数线性回归相关系数P＜0.01,均齐度与流动性指数线性回归相关系数无统计学意义。崩溃角、差角、分散度与喷流性指数相关系数P＜0.01,流动性指数与喷流性指数线性回归相关系数无统计学意义。各类营养素单体存在不同程度物性差异,使营养素单体表现出了不同的流动性与喷流性,流动性指数与喷流性指数间并无直接关联。     

柘树果实的抗乳腺癌活性部分的提取、分离及结构鉴定

为了得到柘树果实中具有抗乳腺癌活性的化合物,以人乳腺癌细胞MDA-MB-231和人乳腺癌细胞MCF-7为细胞模型,通过噻唑蓝（methyl thiazolyl tetrazolium,MTT）比色法评价柘树果实石油醚浸膏、乙酸乙酯浸膏、以及正丁醇浸膏粗提取物部位的功能,实验发现乙酸乙酯部位具有明显的抑制乳腺癌细胞的活性,其对乳腺癌细胞MDA-MB-231和MCF-7的IC50分别为：75.4 μg/mL和66.8 μg/mL。采用Sephadex LH-20柱层析和硅胶柱层析对乙酸乙酯部位进行分离,采用单晶X衍射对得到的化合物进行结构鉴定,得到2 种晶体主成分,分别为4’-O-甲基-吡喃异黄酮、吡喃异黄酮。采用MTT方法对获得的2 种单体进行抗乳腺癌活性研究,发现吡喃异黄酮对乳腺癌细胞MCF-7的生长抑制率达到56.7%。结果表明,柘树果实乙酸乙酯部位含有抗乳腺癌成分,且分离得到2 种类异黄酮化合物,其中吡喃异黄酮体现出一定的抗乳腺癌活性。