From Anatomy to Application: A Comprehensive Review of Nanovesicular Systems for Otic Drug Delivery

The human ear is a complicated organ with unique anatomy and composition. Ototopical administration has become an interest recently. However, an effective drug delivery to the ear is not easy, as there are many otic obstacles such as tympanic membrane, blood labyrinth barrier, endolymph-perilymph barrier, and middle inner ear barriers (oval window and round window). Nanovesicular drug delivery carriers have the ability to entrap hydrophilic and lipophilic drugs, increase drug stability, sustain residence time, enhance otic permeability, and increase bioavailability. The objectives of this review are to describe ear anatomy, different otic diseases, and challenges for ear drug delivery. Also, it discusses different nanovesicular drug delivery systems including their characterization methods, advantages, limitations, and applications in ear drug delivery for the treatment of different ear diseases. These systems can manage solubility, safety, bioavailability, efficiency, and stability issues existing in conventional drug delivery systems.