ABSTRACT
The American Society of Rheology (founded in 1929) defi ned “rheology” as the science of deformation and flow of matter. Deformation describes the change of matter in terms of shape or volume, or both. If the changes due to deformation are at least partly non-reversible, matter flows. The focus of this entry is on introducing the rheology of pharmaceutical systems by providing definitions and terminology, presenting examples of rheological behavior and linear viscoelasticity, and discussing rheological measuring techniques.
