Crystallization Operation for Purification of Active Pharmaceutical Ingredients

Abstract

  The crystallization operation is widely used in pharmaceutical production processes. Crystallization is one of unit operation which deals with crystallization phenomena. Crystal qualities have a huge impact on downstream processes and hence affect the purity and cost of the pharmaceuticals. So it is important to control crystal qualities. The driving force of crystallization is supersaturation. Therefore design strategy of supersaturation is necessary to control the crystal qualities. The crystal qualities strongly depend on the trajectory of solution concentration because crystallization phenomena proceed in non-equilibrium process. In order to understand the relationships between operation condition and product specification, the consideration of both equilibrium and kinetics of crystallization by using phase diagram is necessary. In this paper, the operation design method and operation strategy are introduced to control crystal qualities in crystallization by understanding the influence of a dynamic change of the solution composition on the crystal qualities.