A crystallization process can simultaneously involve varying rates of nucleation, growth, aggregation breakage, attrition, and dissolution throughout the crystallizer vessel – due to significant gradients of temperature, mother liquor concentration, and solids concentration that typically are present. The result is a complex process that is irreversible and often difficult to predict accurately – especially during scale-up or technology transfer to alternative equipment.
The nature of crystallization also makes it difficult to obtain representative samples and perform offline analysis during the course of the crystallization process.
Using FBRM for real-time monitoring of changes in crystal count, dimension and shape is the most reliable method of characterizing nucleation, growth, agglomeration and breakage throughout the entire process.
In situ PVM is also extremely valuable for complete understanding of the complexity of many crystal systems.