Polymerizable Contact Lens Formulations and Contact Lenses Obtained Therefrom
Contact lenses, such as hydrogel contact lenses, are described. The present contact lenses include a lens body that is the reaction product of a polymerizable composition. The polymerizable composition includes one or more monomers and a crosslinker that crosslinks the one or more monomers during polymerization. The polymerization of the one or more monomers occurs in the presence of at least two forms of polyvinyl pyrrolidone, each of the at least two forms of polyvinyl pyrrolidone having a different average molecular weight. The at least two forms of polyvinyl pyrrolidone are associated with the first polymer component in the lens body such that a form of polyvinyl pyrrolidone is released from the lens body for at least eight hours based on in vitro release testing. The present invention also relates to packaging systems for use with such lenses and methods of producing such lenses.
1 . A contact lens, comprising:
a lens body which is the reaction product of a polymerizable composition, the polymerizable composition comprising one or more monomers and a crosslinker that crosslinks the one or more monomers during polymerization to form a first polymer component, and said polymerization taking place in the presence of at least two forms of polyvinyl pyrrolidone, each of the at least two forms of polyvinyl pyrrolidone having a different average molecular weight;
wherein the at least two forms of polyvinyl pyrrolidone are associated with the first polymer component in the lens body such that a form of polyvinyl pyrrolidone is released from the lens body for at least eight hours based on in vitro testing.
2 . The contact lens of claim 1 , wherein the at least two forms of polyvinyl pyrrolidone are present in the polymerizable composition in a total amount from about 1% to about 5% by weight.
3 . The contact lens of claim 1 , wherein a first of the at least two forms of polyvinyl pyrrolidone has an average molecular weight in the range of about 10 kilodaltons to about 50 kilodaltons and a second of the at least two forms of polyvinyl pyrrolidone has an average molecular weight in the range of about 800 kilodaltons to about 1,200 kilodaltons.
4 . The contact lens of claim 1 , wherein the at least two forms of polyvinyl pyrrolidone comprise two forms of polyvinyl pyrrolidone, and a first of the two forms of polyvinyl pyrrolidone has a K-value based on Fikentscher's value of viscosity characteristics equation of about 10 to about 50 and a second of the two forms of polyvinyl pyrrolidone has a K-value of about 80 to about 120.
5 . The contact lens of claim 1 , wherein the form of polyvinyl pyrrolidone is released from the lens body for at least 16 hours based on in vitro testing.
6 . The contact lens of claim 1 , wherein the form of polyvinyl pyrrolidone has a biphasic release profile over a period of about 16 hours based on in vitro testing.
7 . The contact lens of claim 1 , wherein the at least two forms of polyvinyl pyrrolidone comprise a higher molecular weight form of polyvinyl pyrrolidone and a lower molecular weight form of polyvinyl pyrrolidone, and the higher molecular weight form is present in the polymerizable composition in a greater amount than the lower molecular weight form.
8 . The contact lens of claim 1 wherein the at least two forms of polyvinyl pyrrolidone comprise a lower molecular weight form of polyvinyl pyrrolidone and a higher molecular weight form of polyvinyl pyrrolidone, and the lower molecular weight form and the higher molecular weight form are present in the polymerizable composition in a mixture of about 20 to about 40% of the lower molecular weight form and about 60 to about 80% of the higher molecular weight form, and are present in the polymerizable composition in a total amount of between about 1% and about 5% by weight.
9 . The contact lens of claim 8 , wherein the mixture of the lower molecular weight form and the higher molecular weight form of polyvinyl pyrrolidone is present in the polymerizable composition in a total amount of about 2% to about 4% by weight.
10 . The contact lens of claim 1 , wherein a surface friction of the lens body is at least 30% less than a surface friction of a second contact lens comprising the reaction product of an identical polymerizable composition without the at least two forms of polyvinyl pyrrolidone.
11 . The contact lens of claim 1 , wherein a sessile drop contact angle of the lens body is at least 30% less than a sessile drop contact angle of a second contact lens comprising the reaction product of an identical polymerizable composition without the at least two forms of polyvinyl pyrrolidone.
12 . The contact lens of claim 1 , wherein a viscosity of the polymerizable composition is at least 30% less than a viscosity of an identical polymerizable composition with a single form of polyvinyl pyrrolidone of the same molecular weight as a highest molecular weight form of PVP in the mixture and is present at a concentration that is the same as a concentration of the highest molecular weight form in the mixture.
13 . The contact lens of claim 1 , wherein a viscosity of the polymerizable composition is at least 50% less than a viscosity of an identical polymerizable composition with a single form of polyvinyl pyrrolidone of the same molecular weight as a highest molecular weight form of PVP in the mixture and is present at a concentration that is the same as a concentration of the highest molecular weight form in the mixture.
14 . A contact lens package comprising:
a contact lens body, wherein the lens body is the reaction product of a polymerizable composition comprising one or more monomers, at least one crosslinker that crosslinks the one or more monomers during polymerization to form a first polymer component, said polymerization taking place in the presence of a first at least one form of polyvinyl pyrrolidone; and
a packaging solution, wherein the packaging solution comprises an aqueous solution containing an additional at least one form of polyvinyl pyrrolidone.
15 . The package of claim 14 , wherein the first at least one form of polyvinyl pyrrolidone present in the polymerizable composition comprises at least two forms of polyvinyl pyrrolidone, wherein each of the at least two forms of polyvinyl pyrrolidone has a different average molecular weight.
16 . The package of claim 14 , wherein the additional at least one form of polyvinyl pyrrolidone present in the packaging solution is the same as the first at least one form of polyvinyl pyrrolidone present in the polymerizable composition.
17 . The package of claim 14 , wherein the additional at least one form polyvinyl pyrrolidone present in the packaging solution is different from the polyvinyl pyrrolidone present in the polymerizable composition.
18 . The package of claim 14 , wherein the additional at least one form of polyvinyl pyrrolidone is present in the packaging solution at a concentration of at least 500 parts per million.
19 . The package of claim 14 , wherein the at least two forms of polyvinyl pyrrolidone in the polymerizable composition are associated with the first polymer component in the lens body such that a form of polyvinyl pyrrolidone is released from the lens body for at least eight hours based on in vitro release testing.
20 . The package of claim 14 , wherein the package further comprises a base member with a cavity configured to hold the contact lens and the packaging solution, and a seal attached to the base member configured to maintain the contact lens and the packaging solution in a sterile condition for a duration equivalent to a shelf life of the contact lens.
20 . A method for producing a contact lens comprising:
providing a polymerizable composition comprising one or more monomers, at least one crosslinker, and at least two forms of polyvinyl pyrrolidone, each of the at least two forms of polyvinyl pyrrolidone having a different average molecular weight; and
polymerizing the polymerizable composition, providing a lens body.