Advanced Size Distribution Control in Batch Cooling Crystallization Using Ultrasound

The combination of a small sonicated crystallizer operated as a seed generator with a large normal batch cooling crystallizer for growth of the seeds has been investigated. Altering the sonication power and time allows the number of seeds generated to be controlled. By control of the conditions in the large crystallizer, a narrow size distribution of crystals of a controlled size can be obtained. Piracetam was used as the model compound, and various process analytical technologies were used in examining the process. Commercial software was used for determination of the growth kinetics, and it is shown that the model predictions very well match the product size of the experiments.