Direct round window application of gentamicin with varying delivery vehicles: a comparison of ototoxicity.
OBJECTIVE
To evaluate patterns of ototoxic damage sustained from gentamicin applied directly to the round window in varying delivery vehicles.


METHODS
The search for a reliable method of drug delivery to the inner ear continues. Vehicles such as Gelfoam, hyaluronic acid, and fibrin may allow for a more reproducible pattern of ototoxic damage.


METHODS
Histological evaluation of vestibular and cochlear damage was performed on Mongolian gerbils after a known dosage of gentamicin in different delivery vehicles.


RESULTS
Variable ototoxic damage was caused by Gelfoam and fibrin-based vehicles. No ototoxic damage was found in the Healon vehicle. The vehicle of fibrin and Gelfoam combined resulted in severe damage. There was no evidence of selective cochlear or vestibular ototoxicity in any of the vehicles tested.


CONCLUSIONS
The fibrin/Gelfoam vehicle was the only delivery system to produce reliable damage. Ototoxic damage depended on the vehicle. We found no evidence for selective vestibular ototoxicity with gentamicin.
Sheppard
William M
WM
Department of Otolaryngology/Communicative Disorders Unit, SUNY Upstate Medical University at Syracuse, New York, USA.
Wanamaker
Hayes H
HH
Pack
Adam
A
Yamamoto
Satoshi
S
Slepecky
Norma
N
D000287:Administration, Topical; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000009:adverse effects; D016503:Drug Delivery Systems / Q000379:methods; D005337:Fibrin / Q000008:administration & dosage / Q000009:adverse effects; D005781:Gelatin Sponge, Absorbable / Q000008:administration & dosage / Q000009:adverse effects; D005839:Gentamicins / Q000008:administration & dosage* / Q000009:adverse effects; D005849:Gerbillinae; D034381:Hearing Loss / Q000139:chemically induced / Q000188:drug therapy; D006820:Hyaluronic Acid / Q000008:administration & dosage / Q000009:adverse effects; D007759:Labyrinth Diseases / Q000139:chemically induced / Q000188:drug therapy; D023421:Models, Animal; D014677:Pharmaceutical Vehicles / Q000008:administration & dosage* / Q000009:adverse effects; D012405:Round Window, Ear / Q000187:drug effects* / Q000473:pathology
D000900:Anti-Bacterial Agents; D005839:Gentamicins; D014677:Pharmaceutical Vehicles; D005337:Fibrin; D006820:Hyaluronic Acid