Poly(lactide-co-glycolide) Nanoparticles for an Extended Delivery of Bevacizumab to Retina: Formulation and In Vitro Characterization

Retinal diseases are leading cause of visual disability and blindness in the developed world. Improved drug delivery technologies that provide optimum drug level, dose interval and less invasive routes of administration are needed. In the present research work poly(lactide-co-glycolide) (PLGA) nanoparticles loaded with bevacizumab was formulated as an extended ocular delivery to target retina. Bevacizumab loaded PLGA nanoparticles were prepared by double emulsion solvent evaporation method and optimised using design of experiments by employing a 4-factor 3-level Box-Behnken statistical design. The effect of independent variables i.e., PLGA content, PVA concentration, volume of aqueous solution (PVA solution) and sonication time on dependent variables i.e., particle size and polydispersity index (PDI) was determined. The response surfaces plots were drawn by using fitted mathematical model and optimal preparation conditions was derived. Selected compositions of NPs were optimised for encapsulation efficiency and in vitro release. The nanoparticles have a mean particle size from 168.00 +/- 08.67 nm to 362.00 +/- 28.11 nm and PDI from 0.18 +/- 0.06 to 0.45 +/- 0.23. The developed NPs showed an encapsulation efficiency of 68.12 5.1% with a slow and incomplete release of drug till 72 h. The developed PLGA nanoparticles were able to target retina via subconjunctival route with extended release profile thus it will give better patient compliance to treat retinal diseases.