(307d) Coater-Dryer Models

Multi-scale modeling was used to assist with the design and scale up of a process to spray coat tablets with an Active Pharmaceutical Ingredient (API). Three models were implemented- a Discrete Element Model (DEM), a Population Balance Model (PBM), and a Thermodynamic Model. The DEM and the Thermodynamic Model are first principles models; the DEM is used to track the motion of individual tablets to study their mixing and the Thermodynamic Model is used to predict their temperature and moisture. The PBM model is a more coarse-grained model that predicts content uniformity by tracking the coating distribution. The models link operating conditions to the coating quality and uniformity and can be used for virtual experiments to aid in actual experimental condition selection and to map out the design space. The advantages of multi-scale modeling to pharmaceutical process development are demonstrated by the timescale range and mechanistic depth provided by combining the models.