The challenges of drug delivery to the esophagus and how to overcome them

Introduction The incidence of esophageal diseases such as eosinophilic esophagitis, gastroesophageal reflux disease, or esophageal carcinoma has increased significantly in recent years. There is a lack of suitable therapeutic options to enable effective therapy. Areas covered This review addresses the challenges of drug targeting to the esophagus. It describes the physiology of the esophagus, physiological parameters relevant for drug targeting and the pathophysiology of selected diseases of the esophagus. Furthermore, conventional dosage forms such as glucocorticoid-containing solutions or suspensions, inhaler devices and orodispersible tablets are discussed. Innovative drug delivery systems such as stents, mucoadhesive films and 3D printed devices are also presented. Expert opinion Drug delivery to the esophagus presents challenges, especially in terms of the short transit time and the rapid clearance. While conventional dosage forms such as solutions or suspensions offer the advantage of being available quickly and patient-specific, innovative drug delivery systems address the problem of the short transit time and can thus enable long-lasting exposure.