[Dexamethasone pharmacokinetics in perilymph of guinea pig after different topical administrations].
OBJECTIVE
To determine pharmacokinetics profiles of dexamethasone (DEX) in perilymph of guinea pig with different intratympanic administrations, and to provide experimental evidence for clinical choice about administration.


METHODS
Two different topical administrations placing a granule gelfoam soaked with DEX (10 g/L) in the niche of round window of guinea pig and infusing tympanic bulb with DEX solution (10 g/L) were conducted. Perilymph of the scala tympani was sampled 1-6 h after administration. DEX in the samples was assayed with high-performance liquid chromatography.


RESULTS
The concentrations of DEX in perilymph after placing a granule gel-foam soaked with DEX in the niche of round window were significantly higher than that after intratympanic infusing. The half-life time of DEX after placing a granule gelfoam was longer.


CONCLUSIONS
DEX could effectively penetrate round window membrane into perilymph after different intratympanic administrations, and the method of placing a granule gelfoam soaked with DEX in the niche of round window is more effective than that of intratympanic infusing.
Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Second Medical University, Shanghai, 200092, China.
Dongming
D
Hou
Hao
H
Wu
Jun
J
Yang
Ping
P
Zhang
Shunguo
S
Zhang
Jie
J
Chen
D000287:Administration, Topical; D000818:Animals; D003907:Dexamethasone / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006168:Guinea Pigs; D010498:Perilymph / Q000378:metabolism*; D012405:Round Window, Ear
D003907:Dexamethasone