Researchers from the Universität Düsseldorf and University of Twente in The Netherlands used Coherent anti-Stokes Raman spectroscopy to image theophylline molecules, a prehistoric asthma medication, being released from their pills. This pharmacokinetic analysis provides helpful knowledge on how to package pharmaceuticals for best therapeutic effect.
The University of Twente explains:
The results of the study show that there are large differences in the spread of the medicine from different pills. Pills made by pressing tripalmitin have rougher surfaces than those made by extrusion when the surface melts slightly and becomes relatively smooth. The smoother surface does not allow the medicine released from the pill to adhere to it. This is, however, possible with the rougher pills; long, needle-shaped crystals of the medicine even grow on the surface. In the case of a smooth surface, the medicine therefore passes into the environment (and thus into the bloodstream) faster and more easily than in the case of a rough surface.
These data are relevant because the speed with which medicine is released determines how much medicine must be administered and how often. By incorporating medicine in pills in the correct manner, pills can be made that are tailored to delivering specific doses of medicine in a controlled manner, as is the case with drips.
The research group at the University of Twente is measuring pills because it was looking for an industrial application in which label-free measuring (that is, without added markers) is very important; the addition of markers to the medicine alters its diffusion behaviour, making efficacy measurements inaccurate. This is, furthermore, a good example of chemical-specific detection in which the medicine and the pill can be measured separately. It demonstrates that the CARS technique is applicable in a realistic medical/biological environment and not only in gas bundles or solid crystals. The basis created here will enable the imaging of increasingly specific things in cells and increasingly specific molecules (such as for the detection of Alzheimer’s disease in blood).
University of Twente press release: Medicine released from pill filmed…
Abstract in Analytical Chemistry: Chemical Imaging of Oral Solid Dosage Forms and Changes upon Dissolution Using Coherent Anti-Stokes Raman Scattering Microscopy
Image: In the case of a smooth pill surface (the even surface to the left of the image) no crystals have formed even after 120 seconds, whereas in the case of the rough pill surface (to the right and far left of the image) crystals have formed. Images by Maike Windbergs and Martin Jurna