Milling And Micronization Of Pharmaceutical Powders

Size reduction mills are used widely throughout the pharmaceutical industry for the reduction of active ingredients (API’s), as well as bulk pharmaceuticals (BPI’s) and excipients such as lactose, HPMC (hydroxypropylmethyl cellulose) and others. Size reduction is used to increase surface area and improve formulation dissolution properties. It is also used to maintain a consistent average particle size distribution (PSD) for the formulation, thus allowing for a better quality mixture when creating solid dosage forms such as tablets and capsules.

Conventional dry size reduction in the pharmaceutical industry is accomplished by impact. This impact size reduction generally falls into two categories: mechanical impact and impact via fluid energy. Examples of mechanical impact mills are hammer mills and pin mills; while spiral jet mills, loop jet mills, and fluidized bed jet mills are examples of micronizers or fluid energy mills.