UV imaging as a novel, ultrafast chemical mapping tool for pharmaceutical tablet analysis

This paper presents a proof of concept for a novel pharmaceutical analytical tool, which utilizes a UV imaging-based machine vision system in order to rapidly acquire maps showing the components of the inspected uniformly white tablets. Two types of tablets were produced, one containing acetylsalicylic acid and one with caffeine, both consisting of two more excipients. Maps were produced by k-means clustering from the pixel information of UV images taken of the tablets, which is a new approach in this field. The results were then compared to maps acquired using Raman chemical imaging. It was found that the particles recognized on the UV maps are similar to the ones on Raman maps. Furthermore, the developed UV imaging-based machine vision system can investigate entire tablet surfaces in under 4 milliseconds, whereas Raman chemical imaging may take over 19 h to measure just a small fraction of the tablet surface. Therefore, the obtained results confirm that UV imaging could be used to rapidly gather highly informative component distribution maps of tablets, which could provide a novel approach of pharmaceutical tablet analysis in a solid state. • Innovative approach in surface mapping utilizing UV images. • Automated imaging system, with UV ~270nm illumination source. • UV imaging-based spatial and spectral identification of tablet components. • K-means clustering-based image processing algorithm for mapping purposes. • Comparison of UV imaging and Raman chemical imaging-based maps.