Sustained-release devices in inner ear medical therapy.

Local delivery of medicines has been gaining increased popularity over the last several decades. Local delivery offers several advantages over systemic administration of a medicine, including fewer side effects, higher local concentration, and the ability to use more of a given medicine then might be tolerated in a systemic route of administration. Following the success of local medicine administration in other fields, the use of transtympanic medical therapy (local administration to the ear) has been gaining in popularity during the last 2 decades and particularly during the last several years [1]. This increase in popularity has largely focused on the administration of two different medicine classes—gentamicin and steroids. The rationale for local administration of gentamicin has been to allow a minimally invasive treatment of the vertigo associated with Meniere’s disease while avoiding systemic side effects and damage to the contralateral ear [2,3]. The rational for local administration of steroids to the ear has been to avoid systemic side effects and allow a higher local concentration of medicine, with the hope of enhancing the desired effect [4,5]. Transtympanic therapy has been successful for both therapies, and this success has been duplicated in centers all over the world [1–5]. Despite this success, transtympanic administration of medication has not progressed dramatically during the last 20 years. Although newer, low-dose gentamicin therapy has demonstrated significant success for treatment of