Contact drying of particulate pharmaceuticals: modelling and simulation

In order to give a concrete response to the need of predictive contact drying simulation tools in pharmaceutical industry, simulation programs for contact drying of pharmaceutical powders were developed in this thesis work. These are two programs for simulate the two main contact drying operation conditions used in the pharmaceutical industry: vacuum and atmospheric contact drying of agitated beds. The programs give a predictive estimation of drying rate curve and bulk bed temperature during contact drying. Only initial conditions, operating conditions, geometrical data, type of substances, solid phase properties and two parameter for the evaluation of an empirical mixing coefficient, are required as input data. A first validation of the developed programs was made on experimental data from literature, regarding two common pharmaceutical excipient powders, wetted with water and dried in a disc contact dryer. The simulation results show a good agreement with the experimental data