The focus of the OSeeT are enteric coatings (EC) and modified-release (MR) coatings.
The characteristics of the coating layer are revealed via OSeeT:
· Mean coating thickness, progress of coating process.
· Intra-particle and inter-particle coating variability, for quality and homogeneity of the applied coating.
· Roughness, optical quality of the surface.
The Technology behind OSeeT is Interferometry
· OCT is based on white light interferometry
*Broad bandwidth resulting in low-coherence length
*Defines the axial (=depth) resolution
· Light is split into a reference and a probe path
· Optics of sample arm focus light and define lateral (=surface) resolution
· Interference of light reflected back from both paths
· Spectrometer (grating, CCD line scan camera)
· Depth-information is generated from interference fringes by Fourier-transformation (FFT)
· Measurement of a single depth scan