Doehlert experimental design applied to optimization and quality control of a granulation process in a high shear mixer

A quality control study on a placebo granulation prepared in a 10 1 high shear mixer was carried out using a Doehlert design with the introduction of a noise factor (impeller speed). The response surface methodology was used to find the operating conditions leading to a product whose characteristics are not only included in the target range, but also non-sensitive to impeller speed variations. Based on the fact that the impeller speed is an important noise factor in the scale-up process, the above-mentioned operating conditions were chosen for preparation of the granules in 50 1 high shear mixer. The tested operating conditions proved suitable for scaling-up from 10 to 50 1.