Scale TRAnsfer in Pharmaceutical compression: from compaction simulators to rotary presses

• Applicant: Dr. Jan Henrik Finke
• Subject Area: Mechanical Process Engineering ; Pharmacy
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 529883969

In the industrial production of pharmaceutical tablets, production capacity in particular is crucial, along with the quality of the product. However, as throughput increases, the time available for filling and compacting formulations into tablets also decreases. Accordingly, the probabilities for mass and thus dose variations of the tablets as well as tablet defects such as capping or lamination increase with the production speed. In the development of new tablet formulations, often only small quantities of materials are available, so that this cannot be done on an industrial scale machine. For this reason, compaction simulators are currently being used that allow the greatest possible knowledge of underlying mechanisms such as particle deformation with the smallest amounts of material. Although the purpose of these machines is to simulate rotary presses, little research has been published on the precise transfer between the different scales. In particular, die filling is a major challenge here due to the structural and process differences between the machine scales. According to the expertise of the applicants, the French-German STRAP project is dedicated to the reproduction of the two quality-determining sub-processes of filling and compacting on rotary presses on compacting simulators. Through the precise analysis of the processes on both scales and the analytical elaboration of the differences, basic knowledge and descriptive models are to be built up, which should enable a scientifically validated scale transfer. For this purpose, complementary measurement methods (e.g. high-speed recordings, differential pressure measurements on the die) will be established in order to generate exact and transferable knowledge. Comprehensive parameter studies are used to collect data sets, on the basis of which physically meaningful, mathematical models are established. The parameters of these models are to be traced back to powder and geometric machine properties in order to enable generalisable transferability, e.g. to other rotary press scales and new formulations. Following the separate analysis of the filling and compacting processes, the interactions of the filling results with the changes in the compaction results will be correlated to generate cross-subprocess understanding. In this way, the common challenges of lubricant dispersion in the feed frame, the occurrence of tablet defects after compacting and their correlation with each other are also addressed. As a result of this project, a reliable prediction of process parameters and correlated product properties on production scales should be made possible on a scientifically justified basis using tests on compaction simulators.

• DFG Programme: Research Grants
• International Connection: France
• Cooperation Partner: Professor Dr. Vincent Mazel