Structures made crystal clear
The appearance of different crystal structures (polymorphs) in a crystallising substance can be critical to its performance in terms of efficacy, safety and bio-availability. During manufacture, process control factors such as pressure and rate of cooling determine the composition of polymorphs that will occur, and the ability to look at the detailed crystal structures allows an understanding of how the presence or absence of a particular polymorph can alter the characteristics of the finished product.
These properties are particularly important in drug development, as product function will change according to the composition of polymorphs within the formulation. Frequently there will be a predominance of one kind with only a small proportion of others, which makes detecting and characterising them particularly difficult. The specialist facilities at UK-based Daresbury Laboratory, including high intensity X-ray diffraction, and the expertise of its materials characterisation team (known as DARTS) provide an efficient, reliable and cost-effective means of revealing polymorph composition.
The technology has other applications: pharmaceutical companies have adequate protection for their product only if their patent covers all the relevant polymorphic forms. In cases of patent infringement DARTS has been instrumental in providing critical evidence that the polymorphic composition of a drug has been copied.