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Technical and regulatory perspective on acid stage dissolution assessed via optical coherence tomography (Part 2:
Jesús Alberto Afonso Urich1, Raymar Andreina Lara Garcia2, Matthias Wolfgang2
1Research Center Pharmaceutical Engineering GmbH, Inffeldgasse 13, 8010 Graz, Austria; Institute of Process and Particle Engineering, Graz University of Technology, Inffeldgasse 13, 8010 Graz, Austria.
International Journal of Pharmaceutics
|November 7, 2025
Summary
Optical Coherence Tomography (OCT) offers a non-destructive method for pharmaceutical stability testing. This technique accurately measures enteric coating thickness, ensuring drug protection throughout shelf life and demonstrating equivalence to traditional dissolution testing.
Area of Science:
- Pharmaceutical Sciences
- Analytical Chemistry
- Materials Science
Background:
- Pharmaceutical stability testing is crucial for drug development and ensuring product efficacy.
- Enteric coatings protect active pharmaceutical ingredients (APIs) from stomach acid degradation.
- Coating performance and stability over time are critical for maintaining drug protection throughout shelf life.
Purpose of the Study:
- To evaluate Optical Coherence Tomography (OCT) as a non-destructive alternative to traditional acid-stage dissolution testing for pharmaceutical stability.
- To assess the stability of three enteric coating materials over extended periods using OCT for thickness measurement.
- To establish the equivalence between OCT-based thickness measurements and pharmacopeial dissolution testing.
Main Methods:
- Utilized Optical Coherence Tomography (OCT) for non-destructive measurement of enteric coating thickness during stability studies.
- Tested three enteric coating materials (Acryl-Eze®, Aquarius™ Control ENA, Nutrateric®) under accelerated (6-month) and long-term (12-month) stability conditions following ICH Q1A (R2) Guidelines.
- Correlated OCT-measured coating thickness with acid-stage dissolution performance and USP <711>A1 acceptance criteria.
Main Results:
- OCT measurements of coating thickness remained consistent throughout the stability periods.
- OCT-measured thickness correlated with the degree of protection against acid-stage dissolution.
- All formulations met USP <711>A1 criteria, but Aquarius™ Control ENA and Nutrateric® showed significant variability, posing regulatory challenges.
Conclusions:
- OCT is a viable, non-destructive analytical tool for pharmaceutical stability testing, demonstrating equivalence to traditional dissolution methods.
- Establishing equivalence can enhance regulatory compliance, improve quality assurance, and reduce laboratory resource requirements.
- Variability in certain formulations necessitates strategic assessment by Marketing Authorization Holders (MAHs) for regulatory compliance.
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