There is a high demand for drug delivery systems that enable local therapy of esophageal diseases such as eosinophilic esophagitis. For the development of such drug delivery systems, suitable in vitro test procedures are needed that allow a biorelevant characterization of dosage forms. With the help of the new test system presented in this thesis it is now possible to simulate the application site esophagus and to characterize the dissolution behavior of esophageal applied drug delivery systems under special consideration of physiological parameters like salivary flow rate, intensity of peristalsis, and posture of the patient. In this work, the dissolution of mucoadhesive films for esophageal application with the new device was investigated and compared to the results obtained with the compendial standard device (USP 2 apparatus). The results show that the novel test system is a promising tool for the early evaluation of locally applied oral formulations for esophageal application. Copyright © 2021 American Pharmacists Association. Published by Elsevier Inc. All rights reserved.