Monitoring the concentration of flowing pharmaceutical powders in a tableting feed frame

The use of process analytical technology (PAT) tools is increasing steadily in the pharmaceutical industry. Such tools are now located throughout the process. When producing tablets, the tableting step itself may be the ideal moment to assess final product composition. Being the last unit operation in tablet production where the elements are still free flowing, it is relatively straightforward to ascertain the composition of the blend in real time. However, a single probe cannot be expected to monitor the composition of every component of a multicomponent blend. In this study, three PAT tools (light-induced fluorescence spectroscopy, near-infrared spectroscopy and color (RGB) imaging) simultaneously checked the composition of powder blends flowing through the feeding unit (feed frame) of a tablet press. The results demonstrate the potential of these tools in monitoring changes in the concentration of a multicomponent mixture in real time, providing users with means to both scrutinize the process and better understand phenomena occurring inside the feed frame.