US Patent 9392229 Iontophoresis methods

A method of anesthetizing a tympanic membrane of an ear of a patient using iontophoresis is disclosed. The method involves delivering an anesthetizing drug solution to an ear canal of the patient's ear, wherein the drug solution includes an anesthetic and a buffer, and wherein the drug solution has a pH in the range of about 6.5 to about 7.5; and applying an amount of current to the drug solution, wherein the amount of applied current is increased at a rate of less than about 0.5 milliamp per minute until a maximum current is achieved.