This paper deals with an integrated approach between chemical reaction engineering, crystallization and solid-liquid separation to identify optimized conditions to improve the filterability of the API in the final and finishing steps. The simple chemical transformation from the free base to the hydrochloride salt had challenging issues related to the filterability of the salt. A Design of Experiments approach was used to study the problem. The specific cake resistance was measured in the laboratory under a variety of process conditions. The results were used to identify optimized conditions for successful scale-up in the plant.