Protective Mechanisms of Liquid Formulations for Gastro-Oesophageal Reflux Disease in a Human Reconstructed Oesophageal Epithelium Model

PURPOSE: A novel experimental design based on a human-reconstructed oesophageal epithelium (HO2E) model has been applied to quantitively assess the properties of a set of liquid formulations, Device A (Gerdoff(®) Protection), Device B (Esoxx(®) One), and Device C (Marial(®) gel) developed to form a temporary physical barrier on the oesophageal epithelium and modify epithelial permeability so to protect the oesophageal mucosa from refluxate components. METHODS: The formulations were applied to a prewetted HO2E model for 15 min. Then, a 0.5% caffeine solution was applied, and its penetration kinetics was assessed at 1 h and 2 h in acidic environments (pH= 3.3) to mirror exposure of the oesophageal mucosa to acidic reflux in GORD patients. Caffeine permeated into the basolateral compartment (evaluated by HPLC-UV) and Lucifer yellow (LY) permeability were quantified 15 min after application of the caffeine in acidic environments. RESULTS: At the 15 min timepoint, Device A reduced caffeine permeation by 77.2% and LY flux by 30.4% compared to the untreated control and with a faster mode of action than that of the other liquid formulations. Transepithelial caffeine flux was reduced, albeit with different timing and efficiency, by all three compounds up to the end of the 2 hour experiment. At 1 h, Device A reduced the caffeine flux by 79.2%; Device B, by 67.2%; and Device C, by 37%. CONCLUSION: These results confirm the ability of the medical devices tested to interact with the oesophageal epithelium and create a temporary physical protective film for up to 2 hours after their application. The results underline differences in the mechanism of action of the three medical devices, with Device A performing faster than the other formulations. The overall results support the relevance of the reconstructed mucosal model to investigate oesophageal epithelium–product interactions and precisely differentiate liquid formulation performance.