Article extract republished from Dec 2019 issue of Speciality Chemicals magazine
As the demand for formulating products becomes increasingly sophisticated, particularly in industries such as biopharmaceuticals, new technologies are required to replace methods for blending products at a manufacturing scale that are still based on principles of homogenisation by mechanical mixing that were first developed over 100 years ago. Although there have been refinements in the technique, mechanical mixing is still built upon the basic process that 19th century engineers would still recognise. A rapidly spinning blade is used to ‘break up’ the disperse phase substance into the continuous phase. This approach to forming emulsions is fundamentally aggressive and difficult to control. In technical terms, it takes significant energy and results in a formulation with broad particle size distribution and the possibility of a high proportion of particles within the formulation being damaged if ingredients are in any way delicate. Over recent years, the development of microfluidic techniques, where the size of each droplet being ‘dripped’ into a mixture can be precisely controlled to give almost perfect monodispersity, has provided an alternative for the manufacture of high-quality emulsions. However, even when using multiple parallel microfluidic devices, the technique still cannot deliver industrially meaningful volumes.