Solubility-based Approach for Co-crystallization

  • Application note
  • September 24, 2021
About the author

Technobis Crystallization Systems is deeply grateful to Prof. Joop ter Horst for his help with this application note.

Screening for co-crystals with a solubility-based approach

Within the pharma industry active ingredients are commonly formulated as solid dosages, however the properties of the solid form of the actives are not always ideal. Therefore, crystal engineering is often employed to improve properties. Co-crystals are a form of crystal engineering that is gaining an increased level of interest within pharma. Co-crystals are a multicomponent complex, similar to salts, solvates and hydrates, where a second molecule is incorporated into the crystal lattice. However, unlike other complexes, the second molecule must be neutral and not a solvent.

This application note discusses how to set up a systematic approach to screening co-crystals that allows you to collect solubility data fast and reliably.

Content overview:
  • What are co-crystals and why are they interesting?
  • Improved Physicochemical Properties by Co-Crystallization
  • Salt vs Co-crystal
  • Systematic approach to screening co-crystals, using the Crystal16 instrument
  • Constructing phase diagrams
  • Conclusions

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