Systems and methods are provided for sealing an ear canal for retaining a solution in the ear canal. Adhesive earplugs are provided through which the solution can be delivered, and which, following delivery, retain the fluid in the ear canal. The systems and methods may also be useful for delivering an anesthetizing solution to the ear canal of a human patient and for maintaining the solution therein for use with an iontophoresis system for anesthetizing the tympanic membrane.