Anisotropy of strain in pharmaceutically relevant materials for description of brittleness

Understanding the role of pressure during the compaction of tablets is a key challenge for the pharmaceutical industry. Plastic, elastic deformation and fragmentation are all mechanical processes that occur when applying an external stress to a powdered sample. They define the final tablet structure and, ultimately, its quality. The properties of a powder are not only governed by the particle size and shape but also to the property of the crystalline materials. It has been shown that crystalline materials can possess slip planes that can aid the plastic deformation of the solid hence increase its tablettability. Studies have linked the structure to its performance however little is known as to how these materials change as a function of the tabletting pressure. We have started to investigate how pharmaceutical materials change as a function of hydrostatic pressure but the real challenge is understanding the effect of non-hydrostatic pressure which is the focus of this proposal.