Nondestructive evaluation of Polymer Coating Structures on Pharmaceutical Pellets using Full Field Optical Coherence Tomography
Journal of Pharmaceutical Sciences
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Li, C., Zeitler, A., Dong, Y., & Shen, Y. (2014). Nondestructive evaluation of Polymer Coating Structures on Pharmaceutical Pellets using Full Field Optical Coherence Tomography. Journal of Pharmaceutical Sciences https://doi.org/10.1002/jps.23764
Full field optical coherence tomography (FF-OCT) using a conventional LED light source and a CMOS camera has been developed for characterising coatings on small pellet samples. A set of en-face images covering an area of 700µm x 700µm were taken over a depth range of 166 µm. The three-dimensional structural information, such as the coating thickness and uniformity, was subsequently obtained by analysis of the recorded en-face images. Drug loaded pharmaceutical sustained release pellets with two coating layers and of a sub-millimetre diameter were studied to demonstrate the usefulness of the developed system. We have shown that both coatings can be clearly resolved and the thickness was determined to be 40 µm and 50 µm for the outer and inner coating layers, respectively. It was also found that the outer coating layer is relatively uniform whilst the inner coating layer has many particle-like features. X-ray Computed Microtomography (X?CT) measurements carried out on the same pellet sample confirmed all these findings. The presented FF-OCT approach is inexpensive and has better spatial resolution compared to other non-destructive analysis techniques such as terahertz pulsed imaging, and is thus considered advantageous for the quantitative analysis of thin coatings on small pellet samples.
optical coherency tomography (OCT), imaging methods, coating, pellet, excipients
External DOI: https://doi.org/10.1002/jps.23764
This record's URL: https://www.repository.cam.ac.uk/handle/1810/245272