Intratympanic gentamicin injection (ITGI) has gained acceptance worldwide for the treatment of Ménière's disease. Reports assessing the efficacy of ITGI suffer from high variability between patients. This variability may be due to ITGI, which does not permit a sustained diffusion of gentamicin across the round window membrane. The present study investigates the effectiveness of a sustained local hydrogel system on the delivery of gentamicin into the inner ear for the treatment of Ménière's disease.