Single application thixotropic antibiotic delivery systems for otitis externa

Outer ear infections (otitis externa or OE) affect an estimated 10% of people in their lifetime, with associated healthcare costs amounting to over $500 million. The disease has a bacterial etiology, is mostly treatable in the general population with topical antibiotics regimes, and can be supplemented in severe cases with systemic counterparts. However, incorrect application or non-compliance with administration schedule of antibiotics leads to infection persistence, recurrence and potentially, development of antibiotic resistant bacterial strains. In diabetic or elderly patients, the infection can be life threatening as it can progress into necrotizing or malignant otitis externa (MOE), with severe health consequences. In recent years, the incidence rate of MOE has seen a significant increase and has been associated with antibiotic resistant bacterial strains. There is therefore a critical need to develop safe and effective therapies for the treatment of OE and prevention of MOE. Our research is focused on the development of an ototopical antibiotic delivery system that is liquid when sheared and could be deployed easily though a syringe or drop dispenser, but that gels rapidly in place once the shear stress is removed (thixotropic). Such a delivery system would have the benefits of simple and effective topical application, would eliminate the risk of antibiotic administration regime noncompliance, and would deliver in situ active components at effective concentrations.