Evaluation of Human Esophageal Epithelium Permeability in Presence of Different Formulations Containing Hyaluronic Acid and Chondroitin Sulphate

PURPOSE: New medical devices that contain hyaluronic acid (HA) and chondroitin sulphate (CS), with or without antacid components, have been developed for the treatment of gastroesophageal reflux disease (GERD) with the aim of improving oesophageal mucosal defences by creating a film on the oesophageal mucosa and acting as a mechanical barrier against the noxious components of refluxate, both acidic and basic. METHODS: The film-forming and protective efficacy of medical device A based on HA and CS plus aluminium hydroxide, device B combining HA and CS with magnesium trisilicate and device C with only the combination of HA and CS was tested on a reconstructed human oesophageal epithelium (HO2E/S/5) as a biological model in 2 different pH environments, neutral and acidic, to mimic realistic conditions. Caffeine penetration kinetics and Lucifer yellow (LY) permeability modifications induced by these products were compared to those induced by a negative control series (saline solution, code NC) and positive control series (white Vaseline, code V) under neutral and acidic pH conditions. RESULTS: Under neutral and acidic pH conditions, compared to the negative control, all the products tested reduced (>80% and 85–90%, respectively) the caffeine passage, and no significant difference was observed among the products tested. Under neutral and acidic conditions, the LY permeabilities registered with device A and device C were not different from that registered with the negative control, while an LY flux% increase was calculated after 2 hrs of treatment (21.1%) with device B under acidic conditions. CONCLUSION: These results confirm the ability of the products tested to interact with the oesophageal epithelium in order to adhere and create a stable protective film for at least 2 hours after their homogeneous distribution on the epithelium surface. Further clinical studies are needed to test these devices in the topical treatment of gastroesophageal reflux symptoms.