Researcher: Selasi Dogbe
Principal Investigator: Prof. Mojtaba Ghadiri
Co-Investigator(s): Dr Ali Hassanpour, Dr Colin Hare
Industrial Collaborators: Dr David Wilson (AstraZeneca), Dr Richard Storey (AstraZeneca), Iain Crosley (Hosokawa Micron)
Sponsor: AstraZeneca, EPSRC
Status: Ongoing (2013 – )


Spiral jet milling is one of the most widely used size reduction operations, particularly in the pharmaceutical industry, due to its ability to reduce particulate solids to the micron size range and narrow size distribution.  These properties are beneficial as they facilitate diffusion and provide good content uniformity in tablets.  While the spiral jet mill process is very energy intensive, it is not however, efficient.  A very small proportion of the input energy is used in particle breakage, and the overall breakage process is not very well understood.

Using the Discrete Element Method coupled with Computational Fluid Dynamics, the aim of this project is to develop a model to predict the milling behaviour of active pharmaceutical ingredients and excipients in the spiral jet mill, based on the materials’ mechanical properties.  The developed model will be used to quantify the energy utilisation, and to investigate the scale-up rules of the spiral jet mill.

Jet mill simulation