From Raw Data to Process: The Path to a Batch or a Continuous Crystallizer Design for Ibuprofen

To design a crystallizer for producing an active pharmaceutical ingredient (API) of the desired crystal size, it is necessary to know the solubility, the nucleation metastable zone widths (MSZW), the crystal growth rates, and the nucleation rates. These data are available for the popular anti-inflammatory drug ibuprofen crystallized from absolute ethanol and water–ethanol mixtures. Using these data, methods are outlined to design industrial crystallizers to recover ibuprofen crystals. From ethanol, as the solubility increases greatly with temperature, cooling crystallizers can be used industrially. Both seeded batch and continuous designs are considered.