Salústio Paulo J, Monteiro Maria F, Nunes Telmo, Sousa E Silva José P, Costa Paulo J
Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal.
Laboratory of Pharmaceutical Technology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal.
Drug Dev Ind Pharm. 2021 Sep;47(9):1502-1511. doi: 10.1080/03639045.2021.2004158. Epub 2021 Nov 15.
The objective of this work was to analyze the flow behavior of a commonly used filler (pregelatinised starch) and the effect of two of the most used lubricants (talc and colloidal silicon dioxide). The studies were carried out according to the conventional methods (Angle of Repose, Bulk and Tapped densities and from these the Compressibility Index) and shear cell methods (Brookfield Powder Flow Tester apparatus) described in European Pharmacopeia (Ph. Eur.). The results showed some surprising and unexpected values for the flow behavior of this filler under influence of the methods and the used glidants. Regarding pure starch and mixtures containing talc, the flow behavior was similar between them and the Flow Index (ff) values varied between 1.8 and 4 (very cohesive and cohesive) as consolidation stress (σ) increased. In this case, the glidant effect was not observed. However, for the mixtures of starch with colloidal silicon dioxide this effect was observed providing Flow Index (ff) values between 2.6 and 8.9 (cohesive and easy-flowing) as consolidation stress (σ) increased. Other parameters that are also used to characterize flow properties, more specifically, within silos, chutes and hoppers, such as effective angle of internal friction (φe), effective angle of wall friction (φx), critical arching and critical rathole values, provided similar information. Based in the obtained results from all tests it can be said that the talc did not induce improvement on the starch flow behavior in the used conditions in opposition to the effect produced by colloidal silicon dioxide.HighlightsExample 1. A good flowability of powders is needed in order to be compressed/filled;Example 2. The overcome the poor flow it is usual to use glidants;Example 3. CSD improved the pregelatinised starch (Starch 1500®) flow;Example 4. Talc do not have relevant effect in the pregelatinised starch (Starch 1500®) flow;Example 5. Powder FlowTester method showed more complete and consistent results.
这项工作的目的是分析一种常用填充剂（预胶化淀粉）的流动行为以及两种最常用润滑剂（滑石粉和胶体二氧化硅）的影响。研究按照欧洲药典（Ph. Eur.）中描述的常规方法（休止角、松装密度和振实密度，并由此计算出压缩指数）和剪切池方法（布鲁克菲尔德粉末流动测试仪）进行。结果显示，在这些方法和所用助流剂的影响下，这种填充剂的流动行为出现了一些令人惊讶和意想不到的值。对于纯淀粉和含滑石粉的混合物，随着固结应力（σ）增加，它们之间的流动行为相似，流动指数（ff）值在1.8至4之间变化（非常黏聚和黏聚）。在这种情况下，未观察到助流剂效果。然而，对于淀粉与胶体二氧化硅的混合物，随着固结应力（σ）增加，观察到了这种效果，流动指数（ff）值在2.6至8.9之间（黏聚和易流动）。其他用于表征流动特性的参数，更具体地说，在筒仓、溜槽和料斗内，如有效内摩擦角（φe）、有效壁面摩擦角（φx）、临界起拱和临界鼠洞值，提供了类似的信息。基于所有测试获得的结果，可以说在所用条件下，滑石粉并未改善淀粉的流动行为，这与胶体二氧化硅产生的效果相反。
要点
示例1. 为了进行压缩/填充，需要粉末具有良好的流动性；
示例2. 为克服流动性差的问题，通常使用助流剂；
示例3. 胶体二氧化硅改善了预胶化淀粉（Starch 1500®）的流动；
示例4. 滑石粉对预胶化淀粉（Starch 1500®）的流动没有显著影响；
示例5. 粉末流动测试仪方法显示出更完整和一致的结果。
