March 2012
Volume 53, Issue 14
ARVO Annual Meeting Abstract  |   March 2012
Hyaluronic Acid-Containing Silicone Hydrogels: Their Use as Extended Drug Delivery Systems of Hydrophobic Ocular Drugs
Author Affiliations & Notes
  • Myrto Korogiannaki
    Chemical Engineering, McMaster University, Hamilton, Ontario, Canada
  • Heather Sheardown
    Chemical Engineering, McMaster University, Hamilton, Ontario, Canada
  • Footnotes
    Commercial Relationships  Myrto Korogiannaki, None; Heather Sheardown, None
  • Footnotes
    Support  NSERC
Investigative Ophthalmology & Visual Science March 2012, Vol.53, 436. doi:
  • Views
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Myrto Korogiannaki, Heather Sheardown; Hyaluronic Acid-Containing Silicone Hydrogels: Their Use as Extended Drug Delivery Systems of Hydrophobic Ocular Drugs. Invest. Ophthalmol. Vis. Sci. 2012;53(14):436.

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

  • Supplements

Purpose: : While eyedrops are a well-accepted method of delivering drugs to the eye, they suffer from significant limitations including significant losses, low residence times, pulsatile concentration profiles in the tear fluid and the need for patient compliance. The high oxygen permeability of silicone hydrogel (SH) based materials makes them attractive for extended release in front of the eye applications. Based on the hypothesis that the drug release can be controlled by controlling the hydrophilicity of the materials, we have developed a series of hyaluronic acid (HA) modified SH materials that have utility for extended release of hydrophobic ocular drugs.

Methods: : The modified SH that were used consist of a hydrophilic monomer, either hydroxyethyl methacrylate (HEMA) or N,N-dimethylacrylamide (DMAA), a hydrophobic silicone monomer of methacryloxypropyltris (trimethylsiloxy) silane (TRIS) and hyaluronic acid (HA) (7.5 kDa). Ethylene glycol dimethacrylate (EGDMA) was used as the cross-linker. The reaction was performed by UV induced free-radical polymerization. Atropine was used as a model hydrophobic drug. HA and atropine were incorporated into the SH during synthesis with direct entrapment. The hydrogels were analyzed for surface hydrophilicity and equilibrium water content (EWC) in order to determine the effect of HA on these materials. Drug release was monitored and quantified by UV spectroscopy technique.

Results: : The swelling study showed that the incorporation of HA significantly increased the EWC of drug loaded-DMAA/TRIS hydrogels. Based on the results of the captive air bubble study, it was found that the surface of the model SH were more hydrophobic than our previous HA containing materials presumably due to the polyester sheets used for materials casting. Moreover, the presence of HA into the drug loaded-DMAA/TRIS materials improved the surface hydrophilicity as the advancing contact angles were decreased. The contact angles were also examined at the end of the release experiment and it was found that the silicone hydrogel surfaces were significantly more hydrophilic. Atropine was released for more than two weeks and the incorporation of HA during synthesis led to an increase in the amount and the duration of the drug released.

Conclusions: : The HA-containing SH materials have the potential to be used as extended drug delivery systems for hydrophobic drugs with potential application in the treatment of front of the eye diseases as a replacement of eyedrops.

Keywords: contact lens 

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.