Dr Sarah Rough

MA, MEng, PhD

Director of Studies and Special Supervisor

College Jobs

  • Director of Studies, Chemical Engineering
  • Special Supervisor, Chemical Engineering

University Jobs

  • University Senior Lecturer in Department of Chemical Engineering & Biotechnology


Telephone: +44 (0) 1223 334772

Email: slr1002@cam.ac.uk


Dr Rough has been teaching and researching within the CEB Department since the late 1990s, where she is a member of theP4G research group. She is also the Programme Manager for the M.Phil. in Advanced Chemical Engineering. She has been directing the studies of Newnham Chemical Engineering students since 2012.

Research Interests

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 a screen 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 current research looks at the effect of paste preparation and extrusion-spheronisation processing conditions on the mechanism of pellet formation for water-based microcrystalline cellulose (MCC) pastes. The work investigates the parameters that affect the morphology, size and size distribution of the spheronised pellets.