The article is the second in a series in which the collaborators used the Solid Form Suite to compare the hydrogen bonding potential between molecules of the Active Ingredient (AI) on its own versus potential interactions involving the AI and a second component (a co-crystal former). The results confirmed their hypothesis that highest propensity interactions between AI and co-former signal a favourable configuration over the pure forms on their own, and a cocrystal product is likely. However, if AI-AI interactions are preferred, then a co-crystallisation reaction is not likely to be seen. The authors were also able to hypothesise the occurrence of a salt from as a result of proton transfer between AI and co-former, and predict their occurrence as well.
Of the eight attempted experiments, two new co-crystals and four salt forms were obtained. Seven of those eight outcomes were in line with the authors’ expectations, whereas in one experiment no firm case for the occurrence of a co-crystal or a pure form could be made.
About the authors: Dr. Elna Pidcock is a Principal scientific investigator at CCDC; Dr. Peter Galek is a Senior Software Developer at CCDC; Dr. Amit Delori held a post-doctoral position with Prof. Bill Jones at the Pfizer Institute of Pharmaceutical Materials Science, University of Cambridge, and has since moved to University of Strathclyde; Mohit Patni was a University of Cambridge research intern and is now studying at the Indian Institute of Technology, Guwahati.