Diclofenac sodium (DS) nanoparticles were prepared by using a polymer polycaprolactone (PCL) at different concentration and combinations using polaxmer 188 as stabilizing agent. The DS nanoparticles were prepared by using Double Emulsion Solvent Diffusion Technique. The prepared nanoparticles were evaluated by Entrapment efficiency and morphology of DS–PCL particles were studied using TEM. The in vitro release profile of DS nanoparticles containing different ratios of PCL were studied and the release rate were studied. NP1 consist of DS (20mg), PCL(1%), Ethyl acetate(3ml), polaxmer188 (1or2 drops) and polyvinyl alcohol(10ml) was selected as the optimized formulation with sufficient drug–polymer ratio and in–vitro correlation. Nanoparticles of the optimized formulation provided an effective drug concentration at the site of action for appropriate period of time to improve the ocular bioavailability of drug by increasing the pre–corneal residence time.