Dr Sarah Rough

Governing Body Fellow, Director of Studies for Chemical Engineering

I have been teaching and researching within the Department of Chemical Engineering and Biotechnology since the late 1990s, where I am also the Programme Manager for the M.Phil. in Advanced Chemical Engineering. I have been directing the studies of Hughes Hall Chemical Engineering undergraduates since 2001.

My current main research interests lie in the processing of stiff pastes. The majority of my work focuses on the extrusion-spheronisation of pharmaceutical pastes. Many pharmaceutical drugs are administered in the form of a controlled release dose. An effective way of achieving this is by using spherical pellets (about 1 to 2 mm in diameter) of powder/binder. The spheres consist of an excipient, such as lactose or microcrystalline cellulose, and are coated with or contain a small amount of active ingredient. These spheres can be subsequently pressed into tablets or filled into capsules for oral administration. The spheres are usually produced via paste extrusion-spheronisation. Extrudates obtained from an extruder are loaded onto a rotating frictional plate and the paste segments are thus broken up and rounded into spherical pellets. It is important that well-formed spheres of narrow size distribution are generated in order to achieve product dose uniformity and reproducibility. My recent work has focussed upon the parameters that affect the morphology, size and size distribution of the spheronised pellets.

Recent key publication: Parkin, J., Widjaja, K.S., Bryan, M.P., Rough, S.L.
and Wilson, D.I. (2016) Experimental validation of a dimensional analysis of spheronisation of cylindrical extrudates, Powder Technology, 298, 73-83.