ORIGINAL RESEARCH ARTICLE Dexamethasone uptake in v a

ry ability to transtympanically deliver steroids to the middle ear is currently practiced in the treatment of inner ear cataract formation, immunosuppression, psychosis, and avascular necrosis. Combined with the presence of a sig-Grewal et al. Journal of Otolaryngology- Head and Neck Surgery 2013, 42:19 http://www.journalotohns.com/content/42/1/19greater perilymph concentrations than by systemicSciences Centre, University of Toronto, 2075 Bayview Ave, Suite M1-102, Toronto, ON M4N 3M5, Canadadisorders such as idiopathic sudden sensorineural hearing loss, Meniere’s disease, tinnitus, and autoimmune inner ear disease [1–7]. There is also an emerging otoprotective role for transtympanic steroids in cochlear implantation, acous-tic trauma, and with ototoxic chemotherapeutics [8–13]. While systemic administration of glucocorticoids has been nificant chemical blood-labyrinth barrier, these factors have motivated a shift towards injection of steroids directly into the middle ear in attempt to achieve high intra-cochlear drug levels. In order to design and optimize clinical therap-ies however, a detailed understanding of the pharmacokin-etics of steroids in the inner ear is necessary. Animal and human studies have demonstrated that glucocorticoids injected into the middle ear will permeate the round window membrane (RWM), and may achiev