Related Experiment Video
Updated: Aug 8, 2026
A Comparative Study of Drug Delivery Methods Targeted to the Mouse Inner Ear: Bullostomy Versus Transtympanic Injection
Published on: March 8, 2017
Does topical application of 5-fluorouracil ointment influence inner ear function?
Tetsu Iwanaga1, Fujinobu Tanaka, Naoki Tsukasaki
1Division of Otorhinolaryngology, Department of Translational Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Japan.
Objective:
To investigate the effect of 5-fluorouracil (5-FU) ointment on the inner ear of guinea pigs.
Study Design And Setting:
In group A (n = 7), 5-FU ointment was applied into the left external auditory canal. In group B (n = 10), 5-FU ointment was applied to the left middle ear through myringotomy. In both groups, the right ear served as a control. One week later the endocochlear DC potential (EP) was measured and morphology of the cochleae was examined using scanning electron microscopy (SEM) and light microscopy.
Results:
In group A, there was no significant difference between the EP values of the experimental side and the control side. In group B, there was a statistically significant difference between them (P < 0.05). Morphologic findings showed no damage.
Conclusion:
5-FU ointment application to the external ear seems to be safe but its application to the middle ear may pose some risk of ototoxicity.
