Discovering a new polymorph form to treat psychosis

Olanzapine is classed as an antipsychotic drug, commonly used to restore the natural balance of substances found in the brain. It has been used in the treatment of conditions such as schizophrenia and bipolar disorders. 

A molecule that has been extensively studied to assess its solubility, dissolution properties, and bioavailability, olanzapine is known to have over 60 polymorphs.  All solvated and anhydrous forms known to date contain the same SC₀ dimer packing motif. 

A team from GSK and UCL used a new screening approach to force crystallisation from a polymer based molecular dispersion of olanzapine using heat. Computer generated predictions were used to identify polymorphs with suitable (stable) thermodynamic properties and allowed determination of the crystal structure.

The team used simultaneous differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) at Diamond to study the heat-induced crystallisation of olanzapine dispersed in polyvinylpyrrolidone (PVP). They discovered a new polymorph (Form IV) that does not use the SC₀ motif and which exhibits enhanced dissolution properties over Form I.
 

Find out what they discovered.