Controlling Crystal Polymorphism

by in Application Notes, BPS News, BPS Right Sidebar Content

exalt-001Polymorphism can potentially be found in any crystalline material. It is particularly important in the development of pharmaceutical ingredients as different crystal form can have significantly different physical, chemical and biological properties and many drugs receive regulatory approval for only a single crystal form or polymorph.

Dissolution rates for crystalline solids depend on the exact crystal form of a polymorph. High polymorphic purity can be an important requirement, as the presence of even small amounts of a different crystal structure can have detrimental effects: for example in one antiviral drug, not only was one polymorph virtually inactive, its presence in even tiny amounts caused the inactivation of the active polymorph on contact.

Chemists achieve crystallisation by many varied methods. Variation in temperature, solvent, head pressure, seeding method and evaporation rate can all have effects on the crystallisation process, influencing the form, shape and size of crystals formed. However for many methods used there is little control and often no reproducibility of these parameters. Such studies can also be time consuming and difficult to conduct.

exalt-024EXALT is a unique toolkit developed by evaporation experts Genevac and researchers in the field. By enabling a wide range of solvents to be evaporated at the same time and at the same slow rate, the EXALT system can deliver crystalline forms of a compound in a controlled and reproducible manner. It gives control to the operator by removing a number variables which are often present in current methods for crystallisation studies.

EXALT review at Novartis

During the summer of 2013 researchers at Novartis Pharmaceuticals in Horsham, UK, carried out a lengthy evaluation of eXalt technology to investigate how it might be applied to small molecule crystallisation. If you would like more information about the evaluation, please send your request to

More information

Contact Ian Bailey at or 01962 841092 for more information.

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