Decoding powder tabletability: Roles of particle adhesion and plasticity

Tabletability, the ability to make a tablet of adequate mechanical strength by powder compaction, is of paramount importance in the successful manufacture of tablet products. Poor tabletability is a persistent problem in the pharmaceutical industry. Tablet strength can be understood based on a qualitative model where contributions of bonding area and bonding strength are simultaneously considered. Formation and elimination of bonding area is related to compaction conditions, mechanical properties and particulate properties (such as particle size and shape). Plastic deformation emerges as the most important mechanism for creating a large bonding area among deformation mechanisms. Interfacial adhesion defines bonding strength and is dependent on the chemical nature of the materials involved. An analysis of how the chemical, mechanical and physical properties of a powder impact bonding strength and bonding areas leads to an understanding of their effects on powder tabletability. Appropriate use of this model can minimize empiricism in product development and facilitate the design of high quality tablets and robust manufacturing processes.