In recent years, dry granulation using roll compaction (DGRC) attracts considerable interest ofudengineers and researchers, especially in the pharmaceutical industry, due to its distinct featureudthat no liquid binder is needed. It is generally anticipated that as a size enlarge process, DGRCudwould improve properties of feed powders (such as flowability and bulk density), but it wasudalso reported that DGRC could cause a reduction in powder compactibility.udA wide range of powder properties, such as size, shape, flowability, compactibility andudcompressibility, were analysed for several pharmaceutical excipients using the state of artudtechniques. Elastic-plastic properties of single component powders and mixtures were alsouddetermined using the Drucker Prager Cap (DPC) model and an example of FEM applicationudwas presented.udAll the properties determined were used to investigate: 1) the prediction of ribbon milling fromudfriability tests and 2) the effect of granule size on die filling and die compaction behaviour ofudpharmaceutical powders. A new and easy method was developed for predicting fines producedudduring ribbon milling. An exponential relation between the filling ratio and the shoe speed wasudfound. Furthermore, it is shown that flowability is strongly influenced by the granule size, andudthere is a decrease in the tensile strength with the increase of the granule size. Additionally,udfor all the materials analysed a strong correlation between the flow indexes and the criticaludfilling speed was observed and an empirical equation is obtained.
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