Model-based monitoring of an intensified unit for continuous pharmaceutical filtration-drying

Active pharmaceutical ingredient (API) separation from synthesis and crystallization mother liquors is typically carried out in pharmaceutical manufacturing through filtration and drying. These steps are of utmost importance, as impurities herein retained will inevitably end up in the drug product. Recently, a novel carousel has been developed for carrying out filtration and drying in a continuous intensified fashion. The unit represents a step forward with respect to traditional batch filtration and drying, as continuous operation can reduce the variability of the product quality. However, the occurrence of faults compromising product compliance can be assessed only upon discharge of the final cake of API crystals, when its purity can be measured. In this work, we develop a modelbased monitoring system for the unit, based on state and parameter estimation. The implemented monitoring system succeeds in tracking the product critical quality attributes (CQAs), and in detecting common faults for the carousel, such as sudden variations of the feed attributes.