Transtympanic Delivery of Local Anesthetics for Pain in Acute Otitis Media.

Acute otitis media (AOM) commonly causes pain and distress in children. Existing analgesic ototopical drops have limited effectiveness due to the impermeable nature of the tympanic membrane. We developed a local drug delivery system to provide sustained pain relief in patients with AOM, achieved by applying a single dose of a hydrogel formulation onto the tympanic membrane. Successful drug delivery across intact tympanic membranes was demonstrated using the amino-amide anesthetic, bupivacaine, and a highly potent site 1 sodium channel blocker anesthetic, tetrodotoxin. The chemical permeation enhancers incorporated in the delivery system increased the permeability of the tympanic membrane to the anesthetics considerably. The drug levels measured using a previously developed ex vivo model reflect the potential for highly effective local anesthesia.