What term describes the process of reducing particle size?

• A. Diffusion
• B. Aggregation
• C. Crystallization
• D. Comminution

Answer: (D)

Reducing particle size is accomplished through comminution, a mechanical process that breaks particles into smaller pieces. This includes grinding, milling, crushing, and other energy-intensive methods that increase the total surface area of the solid, often improving dissolution rate and uniformity in a pharmaceutical formulation. The other terms describe different phenomena: diffusion is the movement of molecules from areas of high concentration to low concentration, not size reduction; aggregation is particles sticking together to form clumps, which can actually make effective size larger; crystallization is the formation of a solid crystalline phase from a solution or melt, not the act of breaking particles apart.