Developing drug delivery systems, such as the BUCCAL-PEP film that releases medicines, requires very careful control of how they are made and how they perform. Each film must be consistent to ensure it delivers the right dose safely and effectively every time.
There are methods for checking quality during manufacturing, but they can’t always “see” inside the material clearly or deeply enough. This can lead to uneven quality or missed changes that happen over time, such as how the drug film swells, breaks down, or releases its medicine. That’s why Eleftheria Pantazoglou and the DTU team in their latest publication looked into a technique called optical coherence tomography (OCT) to improve quality control in these films.
What is optical coherence tomography?
Eleftheria explains more about the technique: “Optical coherence tomography (OCT) is a non-invasive imaging method that uses light waves to create detailed, cross-sectional pictures of tissues.” Eleftheria and the team tested OCT to study thin drug delivery films of the BUCCAL-PEP project.
The results showed that OCT can accurately measure important features like film thickness and optical properties (which relate to material density and uniformity) without destroying the samples. “By integrating precisely fabricated bilayer film structures with advanced imaging techniques, we can unlock new ways to visualize and understand biological interfaces at high resolution. More broadly, the project underscores the power of combining materials science and biophotonics. When different fields collaborate rigorously, you can achieve insights that neither could alone,” Eleftheria comments.
Uncovering the dynamics of the films
The OCT data provide crucial feedback for quality control of the films and ensuring there are standardised doses of the medicine in the each film. OCT can also monitor how these films dissolve over time, providing insight into how the drug is released. Eleftheria adds: “What I found most striking were the results showing how the individual layers swelled and disintegrated differently over time. Seeing these processes captured so clearly gave us valuable insights into the internal dynamics of the bilayered films – something that’s often difficult to observe directly. It really highlighted how sensitive and informative the imaging approach was for studying material behaviour in realistic conditions.”
A collaborative effort
What did the day-to-day work look like to write this publication? “This was a very collaborative and interdisciplinary project. My day-to-day work involved preparing and optimizing the bilayered film structures – I had previous experience in fabricating films using the RLC coater, so that was a key part of my contribution.
I also had the pleasure of supervising Johan Barfoed, who acted as the bridge between our group and the Biophotonics Imaging group led by Peter Andersen. Gavrielle Untracht and Peter Andersen were Johan’s supervisors from the imaging side, and their expertise was invaluable throughout the project. In our group, Line and I supervised Johan and coordinated closely with the imaging team to bring the different aspects of the work together.”
Next steps
The next steps focus on advancing and refining our prototypes within the BUCCAL-PEP project. “The imaging techniques we developed and applied in this study will be extremely valuable going forward, as they allow us to gain detailed insights into how the prototypes behave and evolve under realistic conditions. This deeper understanding will help us optimize their design and performance more effectively,” Eleftheria explains. This means OCT could become a powerful tool for improving the quality control of the BUCCAL-PEP films.
Curious to read the full publication? Check it out here:
Eleftheria Pantazoglou
Eleftheria is a PhD student at the Pharmaceutical Technology group of the Technical University of Denmark (DTU).
Eleftheria working at the lab
