What relationships govern compactibility in tablet formulations?

The relationship that governs compactibility in tablet formulations is primarily tied to the solid fraction and tensile strength of the tablet. Compactibility refers to the ability of a powder to form a coherent mass under pressure, which is essentially what happens during tablet formation. The solid fraction indicates how much of the tablet volume is occupied by the solid particles after compression, which is crucial for understanding how well the particles will interact and bond together during compaction.

Tensile strength plays a significant role in determining the mechanical integrity of the tablet once it is formed. Higher tensile strength indicates that the tablet can withstand mechanical stresses without breaking, which is vital for its stability during handling and storage. This relationship is important in optimizing formulations to achieve the desired hardness and durability of the final tablet.

While the other options might relate to various aspects of tablet formulation, they do not directly address the fundamental relationships that influence compactibility in the same way that solid fraction and tensile strength do. Particle shape and size distribution, for example, impact flowability and packing density but are not the primary factors influencing the ability of the material to form a compact tablet. Similarly, granule moisture content and flowability are significant for processing, but again, they do not directly define the compactibility as fundamentally as solid