Long-Term Intraocular Delivery of Dexamethasone Using Poly-Epsilon-Caprolactone Intravitreal Implant

Abstract

Purpose: : The objective of this study was to evaluate the long-term safety and pharmacokinetic profile of a dexamethasone-loaded poly-epsilon-caprolactone (PCL) intravitreal implant.

Methods: : The PCL devices were prepared by compression and were inserted in the vitreous of pigmented rabbits. At different time points, vitreous samples were retrieved and dexamethasone concentration was analyzed by high-performance liquid chromatography. The biodegradation of the implants was evaluated by scanning electron microscopy and the dexamethasone remaining was evaluated at the end of follow-up. Clinical and histological examinations were realized to evaluate the implants tolerance.

Results: : PCL implant allows for a controlled and prolonged delivery of dexamethasone in rabbits eyes since it released the drug within the therapeutic range for at least 55 weeks. At 55 weeks approximately 79% of the drug was still present in the implant. Biodegradation study showed that PCL implants degradation is very slow. Clinical and histological observations showed that the devices were very well tolerated in the rabbit eye.

Conclusions: : This study demonstrates the feasibility and tolerance of intravitreous PCL drug delivery systems, which can offer a wide range of applications for intraocular drug delivery because of their controlled and prolonged release over months or even years.

Keywords: corticosteroids • retina • vitreous