The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 24, 2018
Filed:
May. 28, 2014
Novartis Ag, Basel, CH;
Xinming Qian, Johns Creek, GA (US);
Frank Chang, Cumming, GA (US);
Troy Vernon Holland, Suwanee, GA (US);
Yongxing Qiu, Duluth, GA (US);
Venkat Shankar, Alpharetta, GA (US);
Novartis AG, Basel, CH;
Abstract
The invention is related to a method for qualifying and quantifying carboxyl groups on the surfaces of a silicone hydrogel contact lens. The method of the invention comprises the steps of: (a) obtaining silicone hydrogel contact lenses each of which comprises a silicone hydrogel lens body (i.e., bulk material) and a coating thereon, wherein the silicone hydrogel lens body is obtained from a lens formulation free of any polymerizable component including one or more carboxyl groups, wherein the coating comprises a polymer having carboxyl groups; (b) immersing a given number of the silicone hydrogel contact lenses in a fixed volume of a C-Calcohol solution of a positively-charged dye having acetate as counter anion at a given initial concentration for a time period sufficient to stain the silicone hydrogel contact lens; and (c) determining the concentration of carboxyl groups per each silicone hydrogel contact lens and/or the thickness of the coating on the silicone hydrogel contact lens.