Release of betaine and dexpanthenol from vitamin E modified silicone-hydrogel contact lenses.
OBJECTIVE
To develop a contact lens system that will control the release of an osmoprotectant and a moisturizing agent with the aim to reduce symptoms of ocular dryness.


METHODS
Profiles of the release of osmoprotectant betaine and moisturizing agent dexpanthenol from senofilcon A and narafilcon B contact lenses were determined in vitro under sink conditions. Both types of lenses were also infused with vitamin E to increase the duration of drug release due to the formation of the vitamin E diffusion barriers in the lenses. The release profiles from vitamin E-infused lenses were compared with those from the control lenses.


RESULTS
Both dexpanthenol and betaine are released from commercial silicone hydrogel lenses for only about 10 min. Vitamin E loadings into contact lenses at about 20-23% can increase the release times to about 10 h, which is about 60 times larger compared to the control unmodified lenses.


CONCLUSIONS
Vitamin E-loaded silicone hydrogel contact lenses released betaine and dexpanthenol in a controlled fashion.
Department of Chemical Engineering, University of Florida , Gainesville, FL , USA .
Kuan-Hui
KH
Hsu
Percy Lazon
PL
de la Jara
Amali
A
Ariyavidana
Jason
J
Watling
Brien
B
Holden
Qian
Q
Garrett
Anuj
A
Chauhan
D001622:Betaine / Q000493:pharmacokinetics*; D001693:Biological Transport, Active; D003263:Contact Lenses, Hydrophilic; D016503:Drug Delivery Systems; D015352:Dry Eye Syndromes / Q000188:drug therapy; D020100:Hydrogels; D008082:Lipotropic Agents / Q000493:pharmacokinetics*; D064587:Osmoregulation; D010205:Pantothenic Acid / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D012828:Silicones; D014803:Vitamin B Complex / Q000493:pharmacokinetics; D014810:Vitamin E / Q000378:metabolism*
D020100:Hydrogels; D008082:Lipotropic Agents; D012828:Silicones; D014803:Vitamin B Complex; D014810:Vitamin E; D010205:Pantothenic Acid; C007288:dexpanthenol; D001622:Betaine
Betaine; contact lens; controlled release; dexpanthenol; ocular discomfort; vitamin E