Characterising the surface adhesive behavior of tablet tooling components by atomic force microscopy

Purpose: The aim of this study is to develop an atomic force microscopy (AFM) based approach to study the adhesive forces between tabletting punches and model formulation ingredients, that can ultimately be used to understand and predict issues such as sticking during tabletting compression.

Methods: Adhesive interactions were studied between single lactose particles and coated tablet punches. The adhesion was measured at varying relative humidities (RHs) and the influence of surface roughness was investigated. Roughness parameters were measured with AFM imaging and a modeling approach used to predict the influence of roughness on adhesion.

Results: Surface roughness was found to play a significant role in the observed lactose-punch adhesion and the variation of this adhesion across the punch surface. Such differences between punches can be correlated to observations from industrial use. Adhesion forces were spatially mapped to indentify “hot spots” of high adhesion. A modeling approach can predict the relative adhesion of different surfaces from roughness data. The adhesion was also significantly affected by RH, for one type of punch causing a greater than 3× increase in adhesion between 30 and 60% RH. Interestingly, different punches showed different RH-adhesion behavior, relating to their hydrophilicity.

Conclusions: The work introduces a new method for screening tablet punch materials and tabletting conditions. Important factors to be considered when evaluating adhesive interactions in tablet compression have been highlighted. Correlations are observed between AFM adhesion results and tabletting behavior during manufacture. This provides a promising basis for a predictive approach toward combating tabletting issues.     

新媒体不良信息传播机制及对策研究

新媒体在改变人类生活和工作方式的同时,也把风险和挑战留给社会,以智能手机、平板电脑为代表的新媒体终端可能成为传播不良和有害内容的新型平台。文章对新媒体上不良信息的传播机制进行研究,并提出对策建议。     

智能会议管理系统的设计与探索

本文对智能会议管理系统进行了简要概述，并分析了它的技术特点和创新要点。同时结合现有的技术，致力于建立一个基于网络的智能会议管理系统。系统对如何利用信息化、移动化、智能化实现会议系统进行了详细的设计。同时访问迅捷、操作简便、安全可靠是机构信息化建设的又一成果。     

交互式电子会商室的研究

通过分析现代会商室的模式及优缺点,采用大屏幕显示,结合eBeam平板电脑等现有的手笔自然交互工具,加入最新研究的非接触武激光笔交互手段。提出了交互式电子会商室的新型模型。新模式把会商室内参与者合理划分为近、中、远距离三个不同空间,分别采用eBeam、激光笔、平板电脑三种交互工具实现交互式会商,并可随时变换角色。新模式能够使得会商室交流变得更加直观和高效。     

复方次枸橼酸铋片中次枸橼酸铋的含量测定和化学鉴别法

建立了复方次枸橼酸铋片中次枸橼酸铋的化学鉴别方法和含量测定方法。采用配合滴定法测定次枸橼酸铋的含量,考察了片剂中其它主药成分和辅料对滴定的影响情况。方法操作简便,结果准确可靠,回收率为100％,重现性好,RSD<0.13％。     

Estimation of the effective particle sizes within a paper coating layer using a void network model

A range of calcium carbonate-based tablets and paper coating layers, with latex or starch as binder, were prepared. Their dry porous structures were analysed by mercury porosimetry. Some of these samples were also examined by electron microscopy. The porous space of these structures has been simulated using a network model named Pore-Cor, which creates network structures with percolation behaviour and porosity matching those of the experimental sample. Representative particles were grown between the cubic pores and cylindrical throats of the void network model until they touched up to four of the adjacent void features. The sizes of these representative particles, or skeletal elements, have been previously shown to be realistic for the case of unconsolidated sand and glass beads. The size distributions of these skeletal elements were compared with each other and with experiment using a Mann-Whitney test. The sizes of the skeletal elements were found to increase with the particle size of the calcium carbonate powder. The properties of the binders, used in the paper coating formulations, were found to have a major influence on the sizes of the skeletal elements, whose sizes also increased with coating thickness. These findings give insights into the wet structure and the drying process of paper coatings.     

Double regularization control based on level set evolution for tablet packaging image segmentation

This paper proposes a novel double regularization control(DRC) method which is used for tablet packaging image segmentation.Since the intensities of tablet packaging images are inhomogenous,it is difficult to make image segmentation.Compared to methods based on level set,the proposed DRC method has some advantages for tablet packaging image segmentation.The local regional control term and the rectangle initialization contour are first employed in this method to quickly segment uneven grayscale images and accelerate the curve evolution rate.Gaussian filter operator and the convolution calculation are then adopted to remove the effects of texture noises in image segmentation.The developed penalty energy function,as regularization term,increases the constrained conditions based on the gradient flow conditions.Since the potential function is embedded into the level set of evolution equations and the image contour evolutions are bilaterally extended,the proposed method further improves the accuracy of image contours.Experimental studies show that the DRC method greatly improves the computational efficiency and numerical accuracy,and achieves better results for image contour segmentation compared to other level set methods.     

三拗片治疗急性支气管炎(风寒袭肺证)的临床研究

目的: 评价三拗片治疗急性支气管炎(风寒袭肺证)的疗效及安全性。方法: 试验采用随机、双盲双模拟、阳性药平行对照、多中心、非劣性的临床试验方法,共纳入240例受试者,随机分为试验组(三拗片+通宣理肺口服液模拟剂)120例,对照组(通宣理肺口服液+三拗片模拟剂)120例,疗程 7 d。结果: 试验组的临床愈显率、中医证候愈显率及咳嗽、咯痰等单项症状的愈显率均明显优于通宣理肺口服液组(P<0.05);二药对患者咳嗽、咯痰症状的起效时间无统计学差异(P>0.05);三拗片组中医证候总积分治疗后较治疗前降低幅度明显高于通宣理肺口服液组(P<0.05)。结论: 三拗片治疗急性支气管炎(风寒袭肺证)安全有效。     

Evaluation of critical binder properties affecting the compactibility of binary mixtures

The aim of this study was to identify essential physical and mechanical properties of various binders and to investigate their influence on the tensile strength and porosity of tablets made from binary mixtures with sodium bicarbonate. The binders were characterized according to axial and radial tensile strength after compression into tablets, yield pressure and minimum porosity during compression, and elastic recovery after compression. The addition of a binder generally resulted in an increase in the tensile strength and a decrease in the porosity of the sodium bicarbonate tablets. The location of the binder in the voids between the sodium bicarbonate particles thus decreasing the porosity of the tablet seemed to be an important consideration. Consequently, the addition of binders with a low yield pressure value and a relatively small elastic recovery value (e.g., polyethylene glycol 3000 and polyvinylpyrrolidone) resulted in tablets of low porosity and high tensile strength, especially in the axial direction. The tensile strength of the pure binder also seemed to be important, especially for binders with a lower degree of deformability (e.g., microcrystalline cellulose and pregelatinised starch). The results also indicated the value of using both axial and radial tensile strength measurements in assessing the effect of a dry binder and showed that the importance of different binder properties varied according to the direction of the tablet strength measurements. The results demonstrated that the applied characteristics of the binders used in this study may serve as a useful tool in evaluating the effectiveness of binders.     

Comparative studies with Kollicoat MAE 30 D and Kollicoat MAE 30 DP in aqueous spray dispersions and enteric coatings on highly swellable caffeine cores

A film formulation containing Kollicoat MAE 30 D, Kollidon 30, Sicovit Rot 30, titanium dioxide, talc, and a plasticizer for the aqueous manufacture of enteric coatings was studied for the coagulations occurring with certain plasticizers and for differences in resistance on highly swellable caffeine cores. Also included in these investigations were the latices Kollicoat MAE 30 DP and Eudragit L 30 D-55. The coagulations occurring with all three film latices can be attributed to the presence of Kollidon 30 together with certain excipients. Preparations with Kollidon 30, but without color pigments, showed no tendency to coagulate. The advantage of propylene glycol (PG) compared to other plasticizers such as triethyl citrate (TEC) is that no coagulations occurred, even in the presence of Kollidon 30 and color pigments. Among the Kollidon 30-free film formulations examined, a plasticizer content of 10-15% PG or TEC gave the best results. Optimal pigment distribution in the coat originally produced by Kollidon 30 can optionally be achieved by prolonged stirring of the pigment suspension. The resistance can be further improved by inclusion of a subcoating with Kollidon VA 64. Kollicoat MAE 30 D and MAE 30 DP and Eudragit L 30 D-55 showed identical behavior in this study.