OCT has been used for the characterization of pharmaceutical tablet coatings. OCT enables the investigation of thickness and homogeneity, tablet weight gain, and tablet diameters on a single-tablet level. OCT allows rapid evaluation of coating properties, such as thickness and homogeneity independently from variations of the tablet core. In contrast to indirect methods, deviations observed with OCT can be related directly to the coating properties.  The high axial resolution and fast data acquisition rate of OCT has the potential for highly accurate, fast and low-cost coating control during and after manufacturing

Additional general information:

Non-destructive analysis of tablet coatings with optical coherence tomography

An OCT image showing the coating on a drug tablet.

Sequential OCT images during the coating process.