Optical coherence tomography (OCT) has recently been demonstrated to measure the film coating thickness of pharmaceutical tablets and pellets directly. The results enable the analysis of inter- and intra-tablet coating variability at an off-line and in-line setting. To date, only a few coating formulations have been tried and there is very little information on the applicability of OCT to other coatings. As it is well documented that optical methods including OCT are prone to scattering leading to limited penetration, some pharmaceutical coatings may not be measurable altogether. This study presents OCT measurements of 22 different common coatings for the assessment of OCT applicability.