The use of computational fluid dynamics (CFD) in the design of a pharmaceutical processor is described. A simple computational model of the process vessel was developed using a single-phase flow. The results of this preliminary study showed good agreement with experimental tests. The model was further developed to consider the effect of solid particles on the processes occurring within a single vessel pharmaceutical processor. Having obtained converged solutions, the model was used to optimize the design of the processor. The model was used to develop new designs of the vessel. The design optimization was done on the basis of comparisons with conventional pharmaceutical processing equipment. Optimization of the process parameters is important, as they are known to affect the functionality of the final product. The study reported here discusses one step in the design process, showing how changes to the inlet configuration can be modelled to show the potential for improved performance.