[Azone-induced changes on corneal endothelium in rabbits].
OBJECTIVE
To investigate ocular toxic effect of azone at low concentrations in rabbits to determine whether this penetration enhancer has any value for ocular use.


METHODS
0.3%, 0.6%, 0.9% concentrations of azone in an ocular emulsion vehicle were studied. Rabbits in three experimental groups received topical 30 microl of 0.3%, 0.6%, 0.9% azone respectively three times daily for 4 weeks. Rabbits in control group 1 received 30 microl of vehicle without azone as negative control and rabbits in control group 2 received nothing as normal control. Clinical and histopathological examinations of rabbit cornea endothelial cells were made by slit-lamp biomicroscopy, light microscopy and scanning electron microscopy.


RESULTS
No clinical and histopathological evidence of ocular toxicity occurred in all treated and control eyes. The concentration of azone used in this study was 3-9 times higher than that (at 0.1%) at which corneal penetration of hydrophilic compounds can be enhanced enormously.


CONCLUSIONS
Azone has value for incorporation into ocular formulations to increase therapeutic action of many hydrophilic drugs.
Xu
Y
Y
Henan Institute of Ophthalmology, Zhengzhou 450003.
Chen
Z
Z
Song
J
J
Jin
W
W
Li
J
J
D000818:Animals; D001381:Azepines / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004728:Endothelium, Corneal / Q000187:drug effects* / Q000473:pathology / Q000648:ultrastructure; D005260:Female; D008297:Male; D008854:Microscopy, Electron; D011817:Rabbits
D001381:Azepines; C035229:laurocapram