Abstract
Purpose :
Exudative age-related macular degeneration (AMD) is an eye condition wherein new, weak blood vessels start to ‘leak’ resulting in blindness. Monthly intravitreal anti-VEGF antibody injections are used for treatment, which may have deleterious side effects. Ranibizumab is an FDA approved drug for AMD. The goal of this study was to assess the recovery of ranibizumab in the posterior segment of rabbit eyes after topical delivery using novel anti aggregation formula (AAF).
Methods :
Bioidentical ranibizumab at 22.1mg/ml was purchased from IchorBio. Stock ranibizumab was diluted to 5mg/ml in AAF containing 0.1% hyaluronic acid. AAF contains 0.3% NaCl (51.03 mM), 7.5% trehalose (198.24 mM), 10 mM arginine and 0.04% Tween 80, at a pH of 7.40. Eye drops containing 50µl of 5mg/ml ranibizumab were administered to both eyes of New Zealand rabbits (n=8, age 3-5 months) twice daily for 14.5 days. At 14.5 days, rabbits were placed under anesthesia and blood was drawn for serum ranibizumab concentration, and then humanely euthanized. Aqueous humor, vitreous and retina from each eye was recovered and placed into recovery aliquots of AAF. Tissue samples were analyzed by quantitative ELISA as per manufacturer’s instructions using AAF as standard diluent.
Results :
Table 1 summarizes the mean tissue concentration (ng/g) of ranibizumab recovered from serum, aqueous humor, vitreous and retina. In brief, ranibizumab in serum was present negligibly (<0.04). The highest concentration was present in retina (18.0) followed by aqueous humor (7.82) and vitreous (1.47). Gross examination of the rabbit eyes showed no redness or discharge. A control of AAF without ranibizumab would be null.
Conclusions :
We present the feasibility of ranibizumab delivery to the posterior segment using the novel AAF diluent. In vivo topical ranibizumab drug delivery approach may be possible, perhaps with a higher concentrated dose, and may help in minimizing the adverse risks of intravitreal injections.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.