caa a22 4500 477125824 CHVBK 20180405111649.0 cr unu---uuuuu 170330e19970601xx s 000 0 eng 10.1023/A:1012166809583 doi (NATIONALLICENCE)springer-10.1023/A:1012166809583 Kleinebudde Peter Department of Pharmaceutics and Biopharmaceutics, Christian-Albrecht University of Kiel, Gutenbergstr. 76, D-24118, Kiel, Germany aut The Crystallite-Gel-Model for Microcrystalline Cellulose in Wet-Granulation, Extrusion, and Spheronization [Elektronische Daten] [Peter Kleinebudde] Purpose. A new model for the wet-extrusion/spheronization process with microcrystalline cellulose (MCC) is proposed. The crystallite-gel-model is able to elucidate the unique role of MCC in this process. Many other experimental results, which cannot be explained by the standard model of granulation, the liquid saturation model, give evidence for the crystallite-gel-model. Methods. Pellets were prepared from different types of MCC. Water content during extrusion, power consumption and aspect ratio were correlated. X-ray diffractograms of MCC powders, extrudates and pellets were taken in order to provide information on changes at the single crystallite level. SEM-photographs and leaching studies gave additional information on changes at the particulate level of MCC. Results. At the level of MCC powder particles, dramatic changes occurred during extrusion/spheronization. In contrast to this no changes could be observed at the level of individual crystallites. Conclusions. During granulation and extrusion MCC-particles are thought to be broken down into smaller particles and possibly ultimate single crystallites in the presence of water. The crystallite-gel-model serves as the framework for a new interpretation of the wet-extrusion/ spheronization process. Apart from the ability to explain experimental data published previously in the literature it can be used to develop new experimental plans for further research. Consequently, the crystallite-gel-model exhibits explanatory as well as predictive power. Plenum Publishing Corporation, 1997 microcrystalline cellulose nationallicence wet granulation nationallicence extrusion/spheronization nationallicence crystallite-gel-model nationallicence liquid saturation model nationallicence Pharmaceutical Research Kluwer Academic Publishers-Plenum Publishers 14/6(1997-06-01), 804-809 0724-8741 14:6<804 1997 14 11095 https://doi.org/10.1023/A:1012166809583 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1012166809583 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Kleinebudde Peter Department of Pharmaceutics and Biopharmaceutics, Christian-Albrecht University of Kiel, Gutenbergstr. 76, D-24118, Kiel, Germany aut NATIONALLICENCE 773 0- Pharmaceutical Research Kluwer Academic Publishers-Plenum Publishers 14/6(1997-06-01), 804-809 0724-8741 14:6<804 1997 14 11095 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer