[Permeability of different Dexamethasone drugs through round window membrane].
OBJECTIVE
To analysis the effect of sustained delivering two adjuncts alginate sodium (ALG) and carboxymethylated chitosan (CHI) on permeating of dexamethasone (DXM) through experimental apparatus to round window membrane.


METHODS
The experimental apparatus for round window membrane in vitro was designed by simulating the environment of middle ear and scala tympani. Different drugs of DXM sodium included variable concentrations of ALG and CHI were prepared. Using the experimental apparatus, DXM permeating from round window membrane was sampled in 9 hours while its quantities were measured with high performance liquid chromatography, and then different pharmaceutical equations were simulated.


RESULTS
The releasing quantity of control group (without any adjuncts) rose rapidly within 3 hours, and then approximated to balance. ALG (25 g/L) + CHI(4 g/L) or ALG(25 g/L) + CHI(6 g/L) showed the great effect of sustained release, but ALG (25 g/L) alone took the second place. CHI (4 g/L) alone enhanced the transmembranous permeability.


CONCLUSIONS
With the in vitro apparatus, DXM could permeate through the round window membrane. DXM added with appropriate component of ALG and CHI could be good drugs for sustained release.
Liu
Ya
Y
Center of Otolaryngology of People's Liberation Army, Naval General Hospital, Beijing 10037, China.
Sun
Jian-jun
JJ
Kong
Wei-jia
WJ
Jiang
Ping
P
Jiang
Wei
W
D000464:Alginates / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D002463:Cell Membrane Permeability; D048271:Chitosan / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D003907:Dexamethasone / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D020723:Glucuronic Acid / Q000008:administration & dosage / Q000494:pharmacology; D006168:Guinea Pigs; D006603:Hexuronic Acids / Q000008:administration & dosage / Q000494:pharmacology; D066298:In Vitro Techniques; D012405:Round Window, Ear / Q000187:drug effects*
D000464:Alginates; D006603:Hexuronic Acids; C514968:carboxymethyl-chitosan; D003907:Dexamethasone; D020723:Glucuronic Acid; D048271:Chitosan