Bevacizmab is a recombinant antibody against vascular endothelial growth factor which used for treatment of ocular neovascularizations. Unfortunately due to its short half-life in the vitreous, repetitive intravitreal injections are required to maintain the drug efficiency. Accordingly, we have prepared bevacizumab loaded PLGA NPs and evaluated their release profile after the rabbit intravitreal injections to achieve a sustained release drug delivery system.

Bevacizumab was encapsulated in NPs using a modified double-emulsion solvent evaporation procedure. To investigate the in vivo release of bevacizumab NP suspension was injected to the vitreous of albino rabbits. Then at the specific intervals their vitreous samples were taken and analyzed by ELISA test. The probable ocular toxicity of NPs was evaluated by histology tests and electroretinography.

Results revealed that the prepared NPs provided a sustained release bevacizumab for about 50 days and in comparison with Avastin® 1.7 and 2 times increase in bevacizumab vitreous half-life and the areas under the drug concentration-time curve were observed, respectively. The drug vitreous concentration remained above the minimum concentration that completely blocks the VEGF-induced angiogenesis, for more than 6 weeks.

Finally, this formulation may offer improvements in treatment of eye posterior segment neovascularization by decrease the number of intravitreal injections.