Printing crystalline drugs


Printer printing drugs
A group of UK chemists has used a desktop inkjet printer to prepare a metastable form of the anti-epileptic drug carbamazepine. Co-crystals have been prepared by first depositing very small droplets of template solution followed by droplets of the drug solution, which leads to rapid evaporation and crystallisation.1Simon Gaisford of UCL School of Pharmacy, London, who lead the project, told Chemistry World that this polymorph has only been produced previously by layering it molecule by molecule onto a template crystal using vapour deposition.2

‘Desktop inkjet printers offer amazing control of droplet position in order to produce photographic images,’ says Gaisford. ‘So in this instance the technology can really be considered to be more advanced than is needed for crystal templating, although it is evident that the smaller the droplet size and printing resolution the better the potential of the technique.’

Pharmaceutical co-crystals are a relatively new concept that allow two compounds (both drugs, or a drug with an excipient) to be co-formulated in a stable solid form. Often, the properties of the co-crystal are better than either of the individual components alone ­­– for instance, increased long-term stability, faster dissolution or higher bioavailability. Co-crystals show huge potential in drug development, but waiting for compounds to crystallise for screening purposes can take weeks at a time.

Commenting on Gainsford’s work, Victoria Kett, from Queen's University of Belfast, Northern Ireland, remarks ‘This is the first time that a thermal inkjet printer has been used to produce co-crystals. The low cost and simplicity of the approach is extremely attractive. Further, by offering the possibility to design the print output, the approach should lend itself to techniques that are based on, for example, a 96-well plate, or that require specific amounts of material without wastage.’

Both Kett and Gainsford are realistic about challenges ahead. Co-crystal systems that require solvents other than water (or mixtures of ethanol/water) may interact with the plastic cartridges, and it may be hard to control stoichiometry. Gaisford admits that some experimental factors are difficult to regulate, such as solution or stage temperature, and the team hopes to develop a bespoke inkjet system capable of exploring and controlling these experimental factors.

References

  1. 1. A. B. M. Buanz, R. Telford, I. J. Scowen and S. Gaisford, CrystEngComm, 2013, 15, 1031. DOI 10.1039/c2ce26519b
  2. 2. A. J. Florence et al., Chem. Commun., 2011, 47, 7074–7076

 


Related Content

Chemistry World podcast - March 2013

13 March 2013 Podcast | Monthly

news image

Mark Mascal talks about bio-derived chemicals, John Lindon introduces the Phenome Centre and the team cover the latest news

Press P to print

25 June 2013 Feature

news image

Katharine Sanderson looks at the rise of 3D printers to create lab equipment, build biomaterials and much more

Most Read

Better batteries with pure lithium anodes

28 July 2014 Research

news image

Protective carbon nanosphere coating overcomes lithium problems, pointing the way to improved capacity

Takeover battle pushes Allergan to cut R&D jobs

28 July 2014 Business

news image

Besieged by serially acquisitive Valeant, the Botox maker will lay off 1500 staff to propel earnings growth

Most Commented

Bubble wrap could send lab costs packing

23 July 2014 Research

news image

Potential bubbles up across wide range of uses as storage and test vessels, especially for poor countries

Relativity behind mercury's liquidity

21 June 2013 Research

news image

First evidence that relativistic effects are indeed responsible for mercury's low melting point