Pharmaceutical Co-crystals

The application of co-crystal technologies has only recently been recognised as a way to enhance solubility, stability and the IP position with respect to the development of active pharmaceutical ingredients (APIs).

Unlike salt formation, co-crystallisation does not rely on ionisation of the API and the counterion to make a solid. Instead, both components utilise prominent intermolecular interactions, such as hydrogen bonding, to combine and yield a uniform crystalline material. Combining an API with a pharmaceutically acceptable agent in this guest/host manner has become an increasingly attractive route for developing pharmaceutical products. For example, co-crystallisation offers an alternative when salt screening is either unsuccessful or impossible (due to lack of ionisation sites) to improve the physical properties of a drug. Furthermore, exploring the co-crystallisation potential around an API increases the intellectual property protection over a particular drug product; thus, reducing the risk of costly litigation and market erosion. A recent development in the field has not only saw co-crystallisation as an alternative to salt studies, but has also seen its combination with salts to yield co-crystals of salts. Elegant examples of this have been observed in our labs and have allowed us to stabilise previously unstable salt forms and provide further IP protection.

At Pharmaterials, we are at the forefront of co-crystal screening. Our unique co-crystallisation platform follows on from extensive internal research and incorporates a combination of high-through-put grinding, slurrying, evaporation and sonication techniques. In addition to screening, we provide extensive solid form analysis aimed at selecting the most developable pharmaceutical co-crystal. Our services also include advice on scale-up work and IP issues.