Abstract
Purpose: :
The aim of this study is to develop and characterize PLGA nanoparticles of dexamethasone (DEX), hydrocortisone acetate (HA) and prednisolone acetate (PA) using oil in water (O/W) type emulsion and dialysis methods for the treatment of macular edema.
Methods: :
PLGA nanoparticles were prepared using PLGA 5050 (lactide: glycolide:: 50:50; Mw =40,000- 70,000 Da)/ PLGA 65:35; (lactide: glycolide:: 65:35; Mw =40,000- 70,000 Da by dialysis and O/W emulsion/solvent evaporation methods. All nanoparticles were prepared in two batches. PLGA nanoparticles were characterized for surface morphology,entrapment efficiencies, particle size and in vitro release profiles. The release profiles were analyzed by Higuchi’s equation to estimate rate constants associated with drug release. In vitro, cytotoxicity studies of pure drugs against nanoparticles were carried out in ARPE-19 cells.
Results: :
Entrapment efficiencies of DEX, HA and PA were found to be 9.1%, 14.9%, and 15.5% respectively with dialysis method. O/W emulsion/solvent evaporation method resulted in higher entrapment efficiencies 78.2%, 93.1% and 93.6% for DEX, HA and PA respectively. Sustained release of steroids was obtained from the nanoparticles prepared by O/W emulsion/solvent evaporation method. Moreover, steroids entrapped in nanoparticles were found to less cytotoxic in ARPE-19 cell line as compared to pure drug solutions
Conclusions: :
The results indicated that O/W emulsion/solvent evaporation method is superior to dialysis method. From the cytotoxicity studies it can be concluded that, steroid nanoparticles may serve as a better alternative in the treatment of macular edema.
Keywords: macula/fovea • retina • age-related macular degeneration