Amorphous forms – a challenge and an opportunity
Amorphous forms are solid (supercooled liquid) materials which lack the long range order that is a characteristic of crystal forms.
Many new chemical entities are amorphous when first synthesized and it can prove difficult to get them to crysallise. This is often due to the impurity content that exists at that stage of development. It is however important to obtain the crystalline form, as over time it is highly probable that the API will eventually convert to a crystal and if that happens in late development the property changes will potentially invalidation clinical studies carried out up until that time.
The need here is to make amorphous API crystalline and then make logical decisions on development. One such decision may be to develop the amorphous form, which most usually will be stabilized in the amorphous state with excipients as a solid dispersion.
Professor Buckton has had amorphous materials and their characterization as a major research them for many years and is well aware of issues and opportunities related to the amorphous state.
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