Inner ear drug delivery system from the clinical point of view

Conclusion: Three types of inner ear drug delivery systems (DDS) that were ready to be applied in clinics were developed. Objectives: To develop clinically applicable inner ear DDS for the treatment of inner ear disorders. Methods: Inner ear DDS using clinically applicable materials were developed and evaluated. Results: The systemic application of stealth-type nanoparticles encapsulating betamethasone provided superior therapeutic results for the treatment of noise-induced hearing loss compared with the systemic application of betamethasone in mice. Microparticles made of biodegradable polymer (poly (lactic/glycolic) acid, PLGA) encapsulating lidocaine were placed on the round window membrane of guinea pigs, and resulted in reasonable concentrations of lidocaine in the cochlea without serious adverse effects. The phase I/IIa clinical trial of the application of insulin-like growth factor-1 (IGF-1) in combination with gelatin hydrogel on the round window membrane was conducted, recruiting patients with acute sensorineural hearing loss after the failure of systemic application of steroids.