PharmControl - Efficient control of continuous pharmaceutical production lines

Although many of the plant components used in the pharmaceutical industry would in principle allow a continuous operation, the majority of the production processes is still operated in batch mode at the moment. The quality of the intermediate and final products is checked by drawing samples and analyzing them in the laboratory, which is a cost- and time- consuming procedure. This approach leads to large amounts of waste material. Furthermore, the process routes and endpoints are defined with the help of empirically obtained knowledge of the process, which is time consuming as well. The settings which were found via the experiments are not immediately transferable to other processes. A continuous plant operation in combination with in-process control and the implementation of a feedback process control strategy offers many advantages: As the production rate is determined by the duration of production, a scale-up from the laboratory plant to the production plant can be omitted. Consequently, the time span from process development until the time the production and marketing starts is reduced and the period of patent exclusivity is increased. The production plants can be constructed in a more compact fashion, which reduces their space requirements and the investment costs. Due to the shorter transport paths and the elimination of interim storage, many influences which deteriorate product quality are avoided, e.g. segregation. The usage of PAT which is pursued by suggestions of the U.S. Food and Drug Administration (FDA) allows the measurement of critical process parameters. The obtained measurements allow to react on deviations by the development of proper strategies (e.g., by discharging material which does not meet the specifications). Furthermore, the application of feedback control loops is enabled. By means of feedback control, an immediate reaction on deviations of the measured quality attributes is performed, which increases product quality. Goal of the presented project is the realization of a flexible industrial scale continuous line for tablet production from either hot melt extruded pellets or powder raw materials. Mechanistic process models will be developed and used in a model predictive control strategy. This systematic approach allows transferring the developed and implemented concepts to other continuous production lines. The mechanistic models developed during the project can be used in simulation studies, which severely reduce the time required for bringing a newly developed plant into service. The proposed approach enables an increase in product quality and a decrease of waste material by means of the realization of a feedback controlled, fully automated continuous process. Furthermore, flexibility and efficiency are improved and the production costs are reduced. The process understanding gained from a risk-based process analysis and from the model development completes the concept of an efficient and resource oriented process control.