Mechanical properties

Mechanical properties of pharmaceutical solids play a central role in the manufacturing and performance of pharmaceutical products. Mechanical properties also impact tableting process by affecting stress transmission and ejection force during die compaction. Mechanical properties are physical properties of a material that describe its response to the application of an external force. Mechanical properties important to pharmaceutical materials include elasticity, hardness, tensile strength, and fracture toughness. This chapter summarizes several aspects of crystal structure important to understanding crystal mechanical properties. The mechanical properties are important for successful development of drug products. Future research should be focused on better understanding the structure-mechanical property relationship, which is greatly facilitated by advances in nanomechanical testing and X-ray crystallography. Such knowledge is critical for designing new crystals with desired mechanical properties while simultaneously improving or maintaining other desired pharmaceutical properties, such as high solubility, good stability, and low punch sticking tendency.