By John Baumann, head of R&D Advanced Engineering Technologies – Small Molecule, Lonza
Spray drying of amorphous dispersions improves solubility and bioavailability that enables supersaturation in the intestine, driving higher rates of absorption when compared to crystalline drug forms. Additionally, techniques have been developed to allow greater degrees of freedom when selecting process solvents for spray dried dispersion manufacture, including heated processing and volatile acidic/basic compounds to dissolve active pharmaceutical ingredients (APIs) in a wider range of less toxic or hazardous solvents.
Recent advances in spray drying have allowed for additional degrees of freedom in selecting solution compositions to avoid solvents that are either hard to remove from the spray dried powders, are not compendial, or are environmentally harmful and challenging to manage from a waste management perspective. Lonza, a global contract development and manufacturing organization (CDMO), possesses a wealth of expertise in particle engineering, and has pioneered a novel, temperature shift spray drying process that can be applied to APIs that are poorly soluble in organic spray solvents at room temperature. By immediately heating the solution prior to the nozzle for short times (<60 seconds), large solubility increases can be achieved while minimizing degradation of the API. This approach can enable molecules that may have been deemed unable to progress using standard approaches.