Barrier effect of Esoxx® on esophageal mucosal damage: experimental study on ex-vivo swine model

Massimo P Di Simone,1 Fabio Baldi,2,3 Valentina Vasina,4 Fabrizio Scorrano,5 Maria Laura Bacci,5 Antonella Ferrieri,6 Gilberto Poggioli11Department of General Surgery and Transplants, 2Centre for the Study and Therapy of the Esophageal Diseases, 3GVM Care and Research, MCH Cotignola (RA), 4Department of Pharmacology, Alma Mater Studiorum, University of Bologna, Bologna, 5Department of Veterinary Medical Science – DMSVET – University of Bologna, Bologna, 6Clinical Research Department, Alfa Wassermann Spa, Bologna, ItalyAbstract: The aim of the present study was to assess the potential barrier effect of Esoxx , a new nonprescription medication under development for the relief of gastroesophageal reflux symptoms. Esoxx is based on a mixture of hyaluronic acid and chondroitin sulfate in a bioadhesive suspension of Lutrol F 127 polymer (poloxamer 407) which facilitates the product adhesion on the esophageal mucosa. The mucosal damage was induced by 15 to 90 minutes of perfusion with an acidic solution (HCl, pH 1.47) with or without pepsin (2000 U/mL, acidified to pH 2; Sigma-Aldrich). Mucosal esophageal specimens were histologically evaluated and Evans blue dye solution was used to assess the permeability of the swine mucosa after the chemical injury. The results show that: (1) esophageal mucosal damage is related to the perfusion time and to the presence of pepsin, (2) mucosal damage is associated with an increased permeability, documented by an evident Evans blue staining, (3) perfusion with Esoxx is able to reduce the permeability of the injured mucosa, even after saline washing of the swine esophagus. These preliminary results support further clinical studies of Esoxx in the topical treatment of gastroesophageal reflux symptoms.Keywords: bioadhesion, hyaluronic acid, Evans blue dye, animal model, esophagus, reflux esophagitis