Chitosan coated nanoparticles for efficient delivery of bevacizumab in the posterior ocular tissues via subconjunctival administration

In several ocular diseases, vascular endothelial growth factor (VEGF) level has been found to be unregulated. Bevacizumab, an anti-VEGF drug, is the most commonly used off level drug for diabetic retinopathy (DR). The present study was to evaluate the chitosan-coated poly (lactide-co-glycolic acid) nanoparticles (CS-PLGA NPs) for sustained and effective delivery of bevacizumab to posterior ocular tissues. The penetration of NP through sclera was studied by confocal laser scanning microscopy (CLSM). For pharmacokinetic study, bevacizumab loaded NPs were administered into the rat eye through subconjunctival injection (SCJ) and pharmacokinetic parameters were compared to drug solution. CLSM and pharmacokinetic study showed better penetration of formulation and higher concentration of bevacizumab in posterior ocular tissues. In retinopathy model, CS-PLGA NPs by SCJ route showed more reduction of VEGF level in retina than the topical and intravitreal administration of formulation. Thus, CS-coated PLGA NPs can be potentially useful as carriers to target retina.