title: Development of chitosan nanoparticles coated with hyaluronic acid for topical ocular delivery of dexamethasone.
abstract: The present study involved design of dexamethasone-sodium phosphate (DEX) loaded mucoadhesive chitosan nanoparticles for topical ocular delivery to improve its precorneal retention and corneal permeability. The chitosan-sodium tripolyphosphate nanoparticle (CS-NPs) was developed through ionotropic-gelation technique. The developed CS-NPs were coated with hyaluronic-acid (HA) to make discrete, free-flowing NPs and to improve their mucoadhesive characteristics. The particle-size, zeta-potential and polydispersity-index were determined by Malvern-Zetasizer. The average size of the CS-NPs ranged from 305.25±14.29nm (without HA-coating and before freeze-drying) to 400.57±15.23nm (HA-coated and after freeze-drying). Due to the polyanionic nature of HA, reversing of zeta-potentials from +32.55±4.15 to -33.74±3.45 was observed. Polydispersity-indices varied from 0.178±0.067 (before freeze-drying of HA-coated F2) to 0.427±0.028 (after freeze-drying of HA-coated F2). The encapsulation and loading capacity of around 72.95% and 14.51% respectively were found in optimized CS-NPs. In simulated tear fluid 75.84% cumulative amount of released drug was detected and the in-vitro release results suggested the mechanism of drug release was Fickian-diffusion type. The clarity, pH, refractive index, surface tension and viscosity of the suspensions of DEX-CS-NPs were found promising for ocular use. Stability study on nanoparticles revealed no significant changes were observed in particle-size, encapsulation, drug release and physicochemical characteristics at 25°C for 3-months storage.
authors.affiliation: Nanomedicine Research Unit, Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box: 2457, Riyadh 11451, Saudi Arabia. Electronic address: abulkalam21@gmail.com.
authors.forename: Mohd Abul
authors.initials: MA
authors.lastname: Kalam
mesh_terms: D060433:Administration, Ophthalmic; D000287:Administration, Topical; D048271:Chitosan / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D015925:Cryopreservation; D003907:Dexamethasone / Q000008:administration & dosage* / Q000494:pharmacology*; D065546:Drug Liberation; D004355:Drug Stability; D005612:Freeze Drying; D006820:Hyaluronic Acid / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D055672:Static Electricity; D013499:Surface Properties
chemical_list: D020099:Coated Materials, Biocompatible; D003907:Dexamethasone; D006820:Hyaluronic Acid; D048271:Chitosan
keywords: Chitosan nanoparticles; Dexamethasone; Hyaluronic acid; Ocular drug delivery