Abstract
Purpose: :
To evaluate an ocular sustained release system delivered into the eye with iontophoresis.
Methods: :
Iontophoresis experiments were conducted using the VisulexTM iontophoretic system (Aciont, Salt Lake City, UT) on New Zealand white rabbits. Triamcinolone acetonide (TA) was the drug tested in the present study. The TA sustained release system was composed of triamcinolone acetonide phosphate (TAP) and a precipitating cationic counterion. Both the drug and its the counterion were delivered into the eye simultaneously from the cathode and anode, respectively. Iontophoretic delivery of TAP without the sustained release formulation was the control. After the iontophoresis treatments, the rabbits were sacrificed at predetermined time points, and the eyes were enucleated. The amounts of TA and TAP in the eyes after the sustained release iontophoretic treatments and normal iontophoresis treatments were determined with anusing HPLC assay and compared.
Results: :
The half–lives of the drug delivered into the eye with the sustained release formulation were significantly longer than those of the non–sustained release systemwithout the formulation. This suggests the formation of a sustained release depot of the drug in the eye under the experimental conditions employed in the present study.
Conclusions: :
The result demonstrates the feasibility of non–invasive iontophoretic delivery of a sustained release system depot with the VisulexTM system. This device system offers a noninvasive and reproducible means of delivering a sustained release system in ocular drug delivery. These present studies study provides the basis for future studies aimed at delivering therapeutic drugs to the back of the eye for treatment of ocular diseases, such as age–related macular degeneration, posterior uveitis, macular edema, and diabetic retinopathy.
Keywords: choroid: neovascularization • age-related macular degeneration • corticosteroids