Terahertz pulsed imaging of surface variations on pharmaceutical tablets

We present an analysis of terahertz pulsed imaging (TPI) measurements made on pharmaceutical tablets compacted at a range of compression forces. In particular, we investigate the uniformity and local variations in the refractive index on the surface of tablets of different shapes. Through terahertz imaging it has been possible to observe small-scale deviations on tablet surfaces that may have relevance to the quality of tablet manufacture and performance.