This paper outlines a novel technique, based on modern desktop X-ray microtomography (XMT) and image processing, to visualize and quantitatively investigate powder packing and particle movement during compaction, which relate to materials properties and processing conditions of pharmaceutical tablet manufacture by compaction. This technique has been validated by direct comparison with measurements of particle, shape and size by Scanning Electron Microscopy (SEM), and the results are also consistent with predictions made by Discrete Element Method (DEM) computer simulations. The technique has the potential for further quantitative investigation of powder compaction in pharmaceutical powder blends containing multiple components with ranges of particle sizes and shapes.