title: Synthesis and Characterization of Poly(2-hydroxyethylmethacrylate) Contact Lenses Containing Chitosan Nanoparticles as an Ocular Delivery System for Dexamethasone Sodium Phosphate.
abstract: Dexamethasone sodium phosphate (DXP) is an anti-inflammatory drug commonly used to treat acute and chronic ocular diseases. It is routinely delivered using eye-drops, where typically only 5% of the drug penetrates the corneal epithelium. The bioavailability of such ophthalmic drugs can be enhanced significantly using contact lenses incorporating drug-loaded nanoparticles (NPs).
  
  
  
  The mechanism of release from chitosan NPs (CS-NPs), synthesized by ionic gelation, was studied in vitro. The DXP loaded CS-NPs were subsequently entrapped in contact lenses and the optical and drug-release properties were assessed.
  
  
  
  DXP release from CS-NPs followed diffusion and swelling controlled mechanisms, with an additional proposed impact from the electrostatic interaction between the drug and the CS-NPs. The release rate was found to increase with an increase in drug loading from 20 to 50 wt%. However, an inverse effect was observed when initial loading increased to 100 wt%. NP-laden lenses were optically clear (95-98% transmittance relative to the neat contact lens) and demonstrated sustained DXP release, with approximately 55.73% released in 22 days.
  
  
  
  The release profile indicated that drug levels were within the therapeutic requirement for anti-inflammatory use. These results suggest that these materials might be a promising candidate for the delivery of DXP and other important ophthalmic therapeutics.
authors.affiliation: Pharmaceutical and Molecular Biotechnology Research Centre, Department of Science, School of Science and Computing, Cork Road, Waterford, Ireland.
authors.forename: Gautam
authors.initials: G
authors.lastname: Behl
authors.affiliation: Pharmaceutical and Molecular Biotechnology Research Centre, Department of Science, School of Science and Computing, Cork Road, Waterford, Ireland.
authors.forename: Javed
authors.initials: J
authors.lastname: Iqbal
authors.affiliation: Pharmaceutical and Molecular Biotechnology Research Centre, Department of Science, School of Science and Computing, Cork Road, Waterford, Ireland.
authors.forename: Niall J
authors.initials: NJ
authors.lastname: O'Reilly
authors.affiliation: Pharmaceutical and Molecular Biotechnology Research Centre, Department of Science, School of Science and Computing, Cork Road, Waterford, Ireland.
authors.forename: Peter
authors.initials: P
authors.lastname: McLoughlin
authors.affiliation: Pharmaceutical and Molecular Biotechnology Research Centre, Department of Science, School of Science and Computing, Cork Road, Waterford, Ireland. lfitzhenry@wit.ie.
authors.forename: Laurence
authors.initials: L
authors.lastname: Fitzhenry
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D003261:Contact Lenses; D003907:Dexamethasone / Q000031:analogs & derivatives* / Q000737:chemistry; D004337:Drug Carriers / Q000737:chemistry; D016503:Drug Delivery Systems / Q000379:methods; D005782:Gels / Q000737:chemistry; D008689:Methacrylates / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D009883:Ophthalmic Solutions / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*
chemical_list: D004337:Drug Carriers; D005782:Gels; D008689:Methacrylates; D009883:Ophthalmic Solutions; D011108:Polymers; C004180:dexamethasone 21-phosphate; C005044:hydroxyethyl methacrylate; D003907:Dexamethasone; D048271:Chitosan
keywords: chitosan; contact lens; dexamethasone sodium phosphate; eye drops; nanoparticles; transmittance