Adjuvant agents enhance round window membrane permeability to dexamethasone and modulate basal to apical cochlear gradients

Abstract

Glucocorticoids have direct anti-inflammatory, anti-oxidant and anti-apoptotic effects on cochlear hair cells. Cochlear glucocorticoid therapy has gained particular attention for its ability to enhance the protection of residual hearing following hearing preservation cochlear implantation. Local drug delivery methods achieve high drug concentrations within the inner ear fluids but are reliant upon diffusion across the round window membrane. Diffusion has been shown to demonstrate large individual variability. This study explores the role of “adjuvant agents” which when administered with glucocorticoids, enhance inner ear absorption and distribution. Guinea pig cochleae were administered eith..