Application of the Quality by Design Principles for the Development of the Crystallization Process for a Piperazinyl-Quinoline and Definition of the Control Strategy for Form 1

The studies carried out to develop a robust crystallization method for the substituted piperazinyl-quinoline (<b>1</b>) a compound potentially active in the treatment of depression, are described in this contribution. These studies include the control of a solvate that could have potentially formed in the crystallization process. The principles of quality by design (QbD) were applied to generate the process understanding and to define the control strategy for the control of the formation of the solvate during the crystallization. The application of process analytical technology (PAT) tools was key in achieving the desired process control