A study of the effects of the physical characteristics of microcrystalline cellulose on performance in extrusion spheronization.

PURPOSE: Physical characterization and extrusion-spheronization profiles of 11 microcrystalline cellulose (MCC) grades were performed. Correlation between the physical characteristics and extrusion spheronization behavior and pellet quality was performed to determine critical MCC characteristics that influence the water requirement and spheronization water sensitivity for extrusion-spheronization.
METHODS: Extrusion spheronization of MCC-lactose at varying water contents was performed to determine water requirement, spheronization water sensitivity, and the effect of increasing water content on some pellet qualities (pellet flow rate, friability, bulk, and tapped densities) of each MCC grade. MCC physical properties and tapping characteristics were assessed. Correlation between MCC physical properties and its spheronization behavior parameters was performed.
RESULTS: MCC characteristics, such as powder particle size, size distribution, and porosity, were found to have little influence on the extrusion-spheronization process. However, significant correlation was found between void volumes or packing properties of MCC and the water requirement for extrusion-spheronization and pellet qualities.
CONCLUSIONS: A new insight into the action of MCC as a spheronizing aid was discovered. MCC void volume and packing properties play an important role in determining water retention and release during extrusion-spheronization.