The quick spread of process analytical technologies (PATs) paved the way for the application of advanced control strategies in the drug substance and drug product manufacturing which were not accessible before.
Feedback control was developed and applied in various processing steps, ranging from the control of granule size in a twin-screw wet granulator using image analysis based particle size measurement by manipulating the amount of granulating liquid, to polymorphic purity control of batch crystallization processes where the polymorphic content was measured using Raman and temperature cycles were applied for controlled dissolution of the undesired polymorph, as detected by the Raman.
Modeling efforts are focused on the development of on-line and off-line nonlinear model based control strategies. Experimental implementation and testing of the developed algorithms is in the mid-term horizon.