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Updated: Jan 28, 2026

Development of an In Vitro Ocular Platform to Test Contact Lenses
Published on: April 6, 2016
Uptake and Release of Polyvinyl Alcohol from Hydrogel Daily Disposable Contact Lenses
Chau-Minh Phan, Lakshman N Subbaraman1, Lyndon W Jones1
1Centre for Ocular Research and Education (formerly Centre for Contact Lens Research), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada *c2phan@uwaterloo.ca.
Significance:
Polyvinyl alcohol is a wetting agent that could reduce the symptoms of dry eye and contact lens discomfort. Currently, only one lens type, nelfilcon A (DAILIES AquaComfort Plus), releases polyvinyl alcohol. The concept of releasing this agent from contact lenses could be applied to other lens materials.
Purpose:
The purpose of this study was to measure the release of polyvinyl alcohol from commercially available hydrogel daily disposable contact lenses using refractive index and iodine-borate methods.
Methods:
Etafilcon A, omafilcon A, and nelfilcon A were soaked in phosphate-buffered saline and 0.2% trifluoroacetic acid/acetonitile for 24 hours to remove residual blister pack components. The lenses were then incubated in a 10-mg/mL solution of polyvinyl alcohol for 24 hours. After the incubation period, the lenses were placed in 2 mL of phosphate-buffered saline. At specified time intervals, t = 0.5, 1, 2, 4, 8, 12, and 24 hours, the samples were evaluated using refractive index and an iodine-borate assay. Polyvinyl alcohol uptake was determined by extracting the lenses with methanol for 24 hours.
Results:
There were no differences in the uptake of polyvinyl alcohol between lens types (P > .05). The release of this wetting agent for all lens types followed a burst-plateau profile after the first 30 minutes (P > .05). Nelfilcon A had a slightly higher release of polyvinyl alcohol (P < .05) than did etafilcon A but was similar to omafilcon A (P > .05).
Conclusions:
The results suggest that the contact lenses tested in this study have similar efficiency in delivering polyvinyl alcohol.
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