When an Unsuspected Crystallinity Can Ruin Your Biological Testing in Early Discovery: An Example Case

The impact of the crystalline or amorphous structure of a solid on the solubility and pharmacokinetic properties of a drug candidate is always considered by the pharmaceutical industry during the development of a new drug, however, it is not so frequently considered during the early discovery process by organic and medicinal chemists, particularly working at the academia. We want to share, as an example case, the false negative obtained in the biological testing of a solid sample of a tyrosine kinase inhibitor due to an unexpected crystallinity with respect to a solid amorphous batch of the same compound and the experimentation carried out to establish the origin of such inconsistency.