Are some ear drops ototoxic or potentially ototoxic?

In this article we review the literature concerning the capacity of certain substances to cause ototoxicity when administered topically. The ototoxicity experimentally observed in animals only occurs in humans under certain circumstances. It is concluded that many of these products. which are commonly used for treatment in humans, are ototoxic in animals and may also be ototoxic in humans. Therefore, the use of other substances which have the same action but are not ototoxic