Kleinebudde P
Department of Pharmaceutics and Biopharmaceutics, Christian-Albrecht University of Kiel, Germany.
Pharm Res. 1997 Jun;14(6):804-9. doi: 10.1023/a:1012166809583.
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.
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.
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.
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.
提出一种用于微晶纤维素（MCC）湿挤出/滚圆工艺的新模型。微晶-凝胶模型能够阐明MCC在此过程中的独特作用。许多其他无法用制粒标准模型（液体饱和模型）解释的实验结果，都为微晶-凝胶模型提供了证据。
用不同类型的MCC制备颗粒。关联挤出过程中的含水量、功耗和长径比。拍摄MCC粉末、挤出物和颗粒的X射线衍射图，以提供有关单个微晶水平变化的信息。扫描电子显微镜照片和浸出研究提供了有关MCC颗粒水平变化的更多信息。
在MCC粉末颗粒水平上，挤出/滚圆过程中发生了显著变化。与此形成对比的是，在单个微晶水平上未观察到变化。
在制粒和挤出过程中，MCC颗粒在有水的情况下被认为会分解成更小的颗粒，甚至可能是最终的单个微晶。微晶-凝胶模型为湿挤出/滚圆过程的新解释提供了框架。除了解释文献中先前发表的实验数据的能力外，它还可用于制定进一步研究的新实验计划。因此，微晶-凝胶模型具有解释力和预测力。
