Table 1.

Pharmacokinetics of the inner ear.

	Systemic delivery	Local delivery
Absorption	Via stria vascularis and blood labyrinth barrier	Via round window, oval window and bony otic capsule
Distribution	Into inner ear fluid spaces, inner ear tissues; driven by passive diffusion
Metabolism	Via protein binding, enzymatic processes
Excretion	Via loss to fluid spaces in the cochlea, uptake into intercellular spaces, loss to cochlear bloodstream, loss to the cerebrospinal fluid via the cochlear aqueduct, and to the middle ear via the round window and oval window membranes