The characterization of molten materials for pharmaceutical extrusion

processes is an important facet in many stages of product development.

This characterization can be in the form of specific (absolute) rheological determination of an expected phenomenon (flow, temperature dependence, etc.) or a general (relative) ‘‘rating’’ of the system in comparative terms

(expected degradation, product inspection, resistance to process, etc.). An

extremely effective tool that has found application in both of these genres of testing is the torque rheometer system. Although traditionally used for

plastic and food processes, this device has been embraced by the pharma-

ceutical industry to develop and produce wide-ranging formulations for solid

dosage forms.