Wednesday, July 8, 2015

Generate cocrystal ternary phase diagrams to support process design

We love to provide solutions that save customers time.  A good example arises in process and experimental design aimed at formation of cocrystals.

DynoChem already includes tools to support solvent selection for crystallization and these can indicate the effects of solvent choice on API ("A"), coformer ("B") and cocrystal ("AB") solubility, based on a handful of measurements in a few solvents.  We also provide templates for solution-mediated conversion between forms and drug product salt disproportionation in the presence of excipients.

For cocrystals, once solubilities are known, either by measurement or prediction, a DynoChem dynamic model can simulate in a few seconds the time-dependent equilibration of a large set of potential experiments, reducing the need for painstaking and slow lab experimentation.

Figure 1: Process scheme for simulating cocrystallization process; more solid phases may be included as needed

With this model, users can simulate the relative and total amounts of each of the (e.g. three) solid phases that may result from different starting conditions.  Those results can be plotted and summarized on a ternary phase diagram that summarizes the 'regions' of initial composition that lead selectively to formation of the desired phase.

Figure 2: Ternary phase diagram for an example cocrystal system, with a 1:1 cocrystal AB.

Contact if you'd like to discuss using these tools, or related applications to enantiomers and other systems.  Thanks to Dr Andrew Bird for providing the above illustrations.  

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