US Patent 11459479 Method for making coated silicone hydrogel contact lenses

The invention is generally related to a method for producing coated silicone hydrogel contact lenses each of which has a hydrogel coating thereon and a relative high resistance to uptakes of polycationic antimicrobials as characterized by having a polyquaternium-1-uptake of less than 0.40 micrograms/lens. The hydrogel coating is formed by covalently attached a hydrophilic polymeric material onto a base coating of a polyanionic polymer on a SiHy contact lens. In this method, lower polyquaternium-1-uptake is achieved by using a rinse solution with a higher pH and/or a higher ionic strength (higher salt concentration) for rinsing a treated silicone hydrogel contact lens with a base coating of polyanionic polymer.