Biodegradable scleral implant for controlled intraocular delivery of betamethasone phosphate

✍ Scribed by Kunou, Noriyuki ;Ogura, Yuichiro ;Honda, Yoshihito ;Hyon, Suong-Hyu ;Ikada, Yoshito

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 426 KB
• Volume: 51
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/1097-4636(20000915)51:4<635::aid-jbm11>3.0.co;2-o

✦ Synopsis

We evaluated nail-like, biodegradable scleral implants as a controlled intraocular delivery system of betamethasone phosphate (BP) for the treatment of chronic uveitis using pigmented rabbits. The scleral implants, which contained 10% and 25% of BP (weight 8.5 mg; length 5 mm), were made of poly (D,L-lactide-co-glycolide) (PLGA). In vivo release and retinal toxicity after implantation were also studied in pigmented rabbits. The in vitro release studies demonstrated the 10% and 25% BP-loaded scleral implants released BP in a biphasic release pattern for at least 1 month. The BP concentrations in the vitreous and the retina/choroid after application of scleral implants in pigmented rabbit eyes stayed within the concentration range capable of suppressing inflammatory responses for over 1 month. The BP concentration was greater in the retina/choroid than in the vitreous throughout the study. No substantial toxic reactions in the retina were observed by electroretinography. Our findings suggest that the BP-loaded scleral implant may be a promising device for treatment of chronic uveitis.