Method for making contact lenses
View Patent ↗The instant invention pertains to a method and a fluid composition for producing contact lenses with improved lens quality and with increased product yield. The method of the invention involves adding a phospholipid into a fluid composition including a lens-forming material in an amount sufficient to reduce an averaged mold separation force by at least about 40% in comparison with that without the phospholipids.
1. A method for producing a contact lens, comprising: the steps of: (1) providing a contact lens mold, (2) applying to at least a part of a surface of the mold a layer of PEG-ylated phosphatidyl ethanolamines, (3) at least partially drying said layer, (4) introducing a fluid composition into a mold for making a contact lens, wherein the fluid composition comprises a lens-forming material, wherein the lens-forming material is crosslinkable and/or polymerizable by actinic radiation; (5) crosslinking/polymerizing the lens-forming material in the mold to form a lens having a polymer matrix; and (6) separating the mold, wherein the phospholipid or derivatives thereof is present in an amount sufficient to reduce an averaged mold separation force by at least about 40% in comparison with that without the phospholipid or derivatives.
2. The method of claim 1 , wherein the lens-forming material comprises at least one prepolymer.
3. The method of claim 2 , wherein the lens-forming material comprises at least one prepolymer with two or more thiol groups or with two or more ene-containing groups.
4. The method of claim 1 , wherein the prepolymer is a silicone-containing prepolymer or a silicone-free prepolymer.
5. The method of claim 4 , wherein the silicone-containing prepolymer is capable of forming, in the absence of any monomer and/or crosslinking agent, a silicone hydrogel contact lens which has at least one property selected from the group consisting of an apparent oxygen permeability of at least 40 barrers, an lonoflux Diffusion Coefficient, D, of greater than about 1.5.times.10.sup.-6 mm.sup.2/min, an elastic modulus of from about 0.2 MPa to about 2.0 MPa, and a water content of from about 15% to about 80% by weight when fully hydrated.
6. The method of claim 1 , wherein the prepolymer is a water-soluble silicone-free prepolymer.
7. The method of claim 1 , where the PEG-ylated phosphatidyl ethanolamines is at least one member selected from the group consisting of PEG-ylated dipalmitoyl phosphatidylethanolamine (DPPE-PEG), PEG-ylated palmitoyloleoyl phosphatidylethanolamine (POPE-PEG), PEG-ylated dioleoyl phosphatidylethanolamine (DOPE-PEG) and PEG-ylated distearoyl phosphatidylethanolamine (DSPE-PEG).
8. The method of claim 7 , where the PEG-ylated phosphatidyl ethanolamines is PEG-ylated distearoyl phosphatidylethanolamine (DSPE-PEG).
9. The method of claim 1 , wherein the PEG-ylated phosphatidyl ethanolamines is applied in a quantity of from 0.5% to 10% of the fluid composition.
10. The method of claim 9 , wherein the PEG-ylated phosphatidyl ethanolamines is applied in a quantity of from 1.0% to 6.0% of the fluid composition.
11. The method of claim 10 , wherein the PEG-ylated phosphatidyl ethanolamines is applied in a quantity of from 1.5% to 4.0% of the fluid composition.
12. The method of claim 1 , wherein the fluid composition comprises at least one components selected from the group consisting of a polymerization initiator, a visibility tinting agent, a UV-blocking (absorbing) agent, a photosensitizer, an antimicrobial agent, a bioactive agent, a mold releasing agent, and a leachable lubricant.