Biodegradable scleral implants as new triamcinolone acetonide delivery systems

The goal of this study was to develop ocular scleral implants able to release triamcinolone acetonide (TA) overall several months. Scleral discs were manufactured by a compression-molding method using a new synthetic polymer, poly(methylidene malonate) (PMM2.1.2), as matrix. Implants with good mechanical properties adapted for in vivo implantation have been obtained when using high M(w) PMM2.1.2 (100,000 - 150,000 Da) associated with ethoxylated derivatives of stearic acid (Simulsol) or oligomers of methylidene malonate as plasticizer. After implantation in rabbit eyes, scleral implants showed a good ocular biocompatibility. Indeed, the clinical follow-up and ocular inflammation parameters, such as inflammatory cell number and protein content in aqueous humor, demonstrated that implants were well tolerated and did not provoke abnormal inflammation. Implants were able to release significant concentrations of TA in the vitreous and the sclera throughout 5 weeks.