Customized Contact Lens Treatments for in-the-Eye Medication

Hydrophilic polymer (polymacon, alphafilcon-A) and
silicone-based (balafilcon-A) hydrogel contact
lenses, before and after surface modification by
radio-frequency glow-discharge treatment (RFGDT),
were used to monitor methylene blue/silver nitrate
drug-surrogate uptake and elution. Infrared
spectroscopy revealed modified absorption peaks,
accordingly. Energy-dispersive x-ray (EDX) analysis
and inductively coupled argon plasma atomic emission
spectroscopy (ICP) confirmed silver lens depot
concentrations and were employed to measured eluate
concentrations, while visible spectrophotometry and
ICP spectrometry monitored methylene blue and silver
elution rates in static versus simulated eye-blinking
conditions. The conclusions reached are that (1)
initial drug uptake of surface modified lenses
increased in this order: polymacon alphafilcon-A
balafilcon-A lenses; (2) drug release rates of the
polymacon, and alphafilcon-A remained unaffected by
the RFGDT; (3) increased release rates occurred from
the RFGDT-surface-modified balafilcon-A lenses; and
(4) dynamic forces increased the release rates for
all contact lenses.

Autorentext

James M. Fick obtained his B.S. and M.S. in Biomaterials from
the State University of New York at Buffalo. In 2005, James
moved to New Zealand where he continued his quest of knowledge,
at the University of Auckland. Since then, James has tutored a
wide variety of subjects within the Faculty of Engineering.

Klappentext

Hydrophilic polymer (polymacon, alphafilcon-A) and silicone-based (balafilcon-A) hydrogel contact lenses, before and after surface modification by radio-frequency glow-discharge treatment (RFGDT), were used to monitor methylene blue/silver nitrate drug-surrogate uptake and elution. Infrared spectroscopy revealed modified absorption peaks, accordingly. Energy-dispersive x-ray (EDX) analysis and inductively coupled argon plasma atomic emission spectroscopy (ICP) confirmed silver lens depot concentrations and were employed to measured eluate concentrations, while visible spectrophotometry and ICP spectrometry monitored methylene blue and silver elution rates in static versus simulated eye-blinking conditions. The conclusions reached are that (1) initial drug uptake of surface modified lenses increased in this order: polymacon < alphafilcon-A < balafilcon-A lenses; (2) drug release rates of the polymacon, and alphafilcon-A remained unaffected by the RFGDT; (3) increased release rates occurred from the RFGDT-surface-modified balafilcon-A lenses; and (4) dynamic forces increased the release rates for all contact lenses.