A Novel Imaging Technique to Investigate the Influence of Atomization Air Pressure on Film-Tablet Interfacial Thickness

A novel X-ray photoelectron spectroscopic (XPS) technique combined with principal component analysis of spectra-to-image datasets was employed to study the effects of atomization air pressure used during the coating process on film-tablet interfacial thickness. Placebo tablet cores were prepared and coated with Eudragit RL 30 D. Atomization air pressure was varied from 10 to 20 psi, whereas all other processing parameters were held constant. Higher air pressures generally produced thinner interfaces, although the interfacial region was not uniform across the tablet surface and was dependent on the sampling location. These results demonstrate the suitability of this XPS technique to study the coating-tablet interface. Moreover, the variability in the interfacial thickness illustrates the need to further study such systems.