Permeability of round window membrane and its role for drug delivery: our own findings and literature review

We investigated the pharmacokinetics of caroverine in the perilymph, cerebrospinal fluid and plasma after systemic and local administrations in guinea pigs by using high-performance liquid chromatography. Auditory brainstem responses were measured to evaluate auditory functional effect. The results showed that local application was a both safe and efficient method. We further reviewed literature and pinpointed that the round window is effectively local drug delivery means for future inner ear treatment.