Visualizing liquid transport through coated pharmaceutical tablets using terahertz pulsed imaging

Terahertz pulsed imaging (TPI) was used to visualize the live liquid penetration process of coated pharmaceutical tablets. Multiple features are observed including diffusion through both coating and core layer, with a discontinuity at the core-coating interface as well as the dissolution of the interface. They can all be conveniently quantified, compared and related back to processing parameters such as porosity of the core and other results from the terahertz scan. This study has the potential to facilitate a more in-depth understanding of the impact of coating on drug release and dissolution.