Guest Column: Powder Characterization Techniques For Wet Granulation Applications

By Tim Freeman, Freeman Technology

Wet granulation is a routine unit operation within the pharmaceutical industry, and a common precursor to tableting. It is typically carried out as a batch process, with endpoint detection an important issue. Here, dynamic powder rheometry offers proven benefit. By providing sensitive detection of the transition from wet mass to granulate, using a property that is independent of scale, this powerful analytical technique accelerates scale-up and over the longer term improves manufacture.

High shear mixers tend to be the preferred choice for wet granulation. After initial blending of the dry constituents, a solution is added to wet the blend and promote granulation to a desirable endpoint. Control is achieved by manipulating the amount of granulation solution added, the rate of addition, processing time and the impeller speed.