Feedback control in high shear granulation of pharmaceutical powders

A novel system has been developed to control granule growth in high shear granulation. The system basically consisted of an image-processing device and a fuzzy control system. A computer-controlled image processor, an air purge unit, a high-energy xenon lighting system and an image probe with a CCD camera comprised the image processing device. A fuzzy control system using a linguistic algorithm employing if-then rules with a process lag element taken into consideration has been developed to accurately control granule growth without any excessive growth. This newly developed system was applied to actual high shear granulation of pharmaceutical powders and validity of the system was investigated. It was found that the system could control granule growth with high accuracy, regardless of changes in physical properties of starting materials and the operating conditions.