Ensuring drug-crystal formation

Engineers at Leeds University have developed a simple technology that can be used in existing chemical reactors to ensure ‘right first time’ drug-crystal formation.

Engineers at Leeds University have developed a simple technology that can be used in existing chemical reactors to ensure ‘right first time’ drug-crystal formation.

Ensuring drug crystals are formed correctly is crucial to their efficacy and the efficiency of pharmaceutical manufacturers’ operations.

‘We’ve shown that we can produce a well-defined crystal structure using a self-assembled monolayer bound onto a metal substrate within a regular reactor. This is exciting stuff, because it’s a relatively simple system but could make a huge difference in the efficiency of drug manufacture,’ said Prof Kevin Roberts of the university’s Faculty of Engineering.

One of the first stages of the crystallisation process is called nucleation. During nucleation, particles are introduced into a reactor to encourage the formation of crystals. However, the way in which this is currently carried out is difficult to control and can often lead to the wrong shape, size or structure of drug crystal, something that affects the usefulness and efficacy of the compound.

The system developed by the Leeds team, working alongside Ana Kwokal from Croatian pharmaceutical company PLIVA, has shown that introducing a self-assembled monolayer – a layer of self-organising molecules that is attractive to the substance being crystallised – into a reactor enables consistent crystal formation.

Prof Roberts said: ‘Because this is a really simple solution to ensuring consistent crystallisation, it has huge potential commercially. Our next steps are to make sure it’s just as efficient on an industrial scale.’

This work draws on previous research and experimental systems developed through the Chemicals Behaving Badly II initiative, an Engineering and Physical Sciences Research Council (EPSRC) programme that includes universities and industrial partners.