Intravitreal bromfenac liposomal suspension (100 μg / 0.1 ml). A safety study in rabbit eyes

INTRODUCTION

There is a need to find alternative treatments for MEe. Bromfenac has shown promise in inhibiting the COX-2 enzymatic pathway that partially causes the inflammatory cascade which contributes to the precipitation of ME. However, like other NSAID's, its intraocular half-life is limited. We hypothesize that a delayed-release liposome formulation containing bromfenac might provide a similar anti-inflammatory effect as long-lasting steroid release systems without the well-known steroidal side-effects. We introduced a novel formulation with these characteristics into the vitreous cavity of rabbit eyes in order to evaluate its safety profile.

MATERIAL AND METHODS

10 left eyes of rabbits were injected with the liposome-encapsulated bromfenac suspension (100 μg/0.1 ml). Basal ERG's were recorded. Total follow-up time was 3 months, at which point ERG's were repeated and eyes were enucleated for histopathological study. Total amplitude and implicit times were recorded. A difference of 25% in either recording was considered significant. Significance was assessed using the paired-t test and Wilcoxon matched-pairs signed-rank test. A p-value of <0.05 was considered significant.

RESULTS

No significant changes were recorded in ERG measurements after 3 months when compared to basal measurements. Histopathological analysis of retinal specimens found no traces of liposome-induced toxicity.

CONCLUSION

The liposome-encapsulated bromfenac suspension (100 μg/0.1 ml) is not toxic and has been proven safe to use in an animal model. Therefore, this formulation shows promise as a possible future alternative treatment for ME and should be further studied to show its biological effect and efficacy.