Contact lens formulations and contact lenses

Abstract

A silicone hydrogel contact lens formulation is described. The formulation has a silicone component and a silicone-free component. The silicone component comprises two or three compounds represented by Formula 1, Formula 2, or Formula 3. The silicone-free component comprises a methacrylate component and an N-vinylamide component. The methacrylate component comprises hydroxybutyl methacrylate (HOB) and isobornyl methacrylate (IBM). The N-vinylamide component comprises N-vinyl N-methylacetamide. When compounds of Formula 1 and Formula 2 are present in the formulation in a specific ratio relative to each other, a desirable silicone hydrogel contact lens is obtained by providing specific amounts of HOB and IBM to achieve the specific ratio. A silicone hydrogel contact lens is also described.

Description

Technology Field

[0001] The present invention relates to a novel silicone hydrogel contact lens formulation and a silicone hydrogel contact lens comprising an ophthalmic lens, particularly a contact lens, more particularly a reaction product of a polymerizable composition. Background Technology

[0002] Silicone hydrogel contact lenses have proven to be an acceptable alternative to hydrogel contact lenses. Contact lens manufacturers often introduce new contact lenses to meet market demands. Therefore, there is a continuous need to develop new silicone hydrogel contact lenses to address these needs.

[0003] When developing silicone hydrogel contact lenses, it is difficult to predict whether a new formulation will produce clinically acceptable silicone hydrogel contact lenses. Various changes in lens chemistry, lens design, and manufacturing processes influence the achievement of successful fit, acceptable levels of comfort, acceptable handling experience, and acceptable visual improvement. For example, altering the formulation of a silicone hydrogel contact lens can change oxygen permeability, water content, lens surface wettability, and mechanical properties such as modulus, tensile strength, and elasticity. Therefore, it is impossible to predict which combination of chemicals in the formulation will bring about the desired lens characteristics.

[0004] summation

[0005] The present invention addresses this ongoing need. The inventors discovered that when a specific combination of specific polysiloxane compounds is used in a silicone hydrogel contact lens formulation, it is necessary to adjust other monomers of the formulation in a previously unknown manner to achieve specific desirable contact lens properties. The disclosure herein describes the invention in more detail.

[0006] The applicant has confirmed that a suitable silicone hydrogel contact lens formulation can be formed using a reaction mixture comprising a silicone component and a silicone-free component. The silicone component comprises two compounds, Formula 1 and Formula 2, and preferably consists essentially of these:

[0007] Chemical formula 1

[0008]

[0009] Here, R1 is selected from hydrogen or a methyl group; R2 is hydrogen or C 1-4 Selected from hydrocarbon groups; m represents an integer from 0 to 10; n represents an integer from 4 to 100; a and b represent integers greater than or equal to 1; a+b is 20 to 500; b / (a+b) is 0.01 to 0.22, and the composition of the siloxane unit includes a random composition;

[0010] Chemical formula 2

[0011]

[0012] Here, n is an integer from 10 to 25.

[0013] It is important that the compound of Formula 1 and the compound of Formula 2 are present in a ratio of 50:50 to 77:23 and in a combined amount of 45 to 55 weight percent. Preferably, the ratio of the compound of Formula 1 to the compound of Formula 2 is 53:47 to 77:23.

[0014] In certain embodiments, in the compound of Formula 1, R1 is selected from hydrogen or a methyl group; and R2 is hydrogen or C 1-4 Selected from hydrocarbon groups; m is 0; n represents an integer from 4 to 15; a represents an integer from 50 to 250, and b represents an integer from 5 to 50; the composition of the siloxane unit includes a random composition, wherein the ratio of a:b is 5:1 to 30:1, preferably 10:1 to 20:1.

[0015] In an additional embodiment, the silicon component further comprises an additional silicon compound of Formula 3:

[0016]

[0017] Here, m represents an integer from 3 to 12, n represents an integer from 1 to 10, and R 1 is selected from alkyl groups having 1 to 4 carbon atoms, and R 2 is a hydrogen atom or a methyl group, and R 3 It is a hydrogen atom or a methyl group.

[0018] In some embodiments, in the compound of Formula 3, m is 4, n is 1, and R 1 is a butyl group, and R 2 is H, and R 3 It is a methyl group.

[0019] If a compound of Formula 3 is present, it is used in an amount of less than 1% of the total contact lens formulation. In one preferred embodiment of the formulation, the silicone component is essentially composed of Formula 1, Formula 2, and Formula 3.

[0020] The combination of compounds of Chemical Formula 1 and Chemical Formula 2 produces a contact lens that still has good oxygen permeability while allowing a smaller amount of silicone component to be used, which is advantageous. This also enables a high water content, which is beneficial for wettability.

[0021] However, when a contact lens formulation is prepared using compounds of formulas 1 and 2, even with such smaller amounts, the tensile strength and Young's modulus can be high, as shown in Examples 15 to 17 of US8129442.

[0022] The applicant has confirmed that by concentrated selection of the ratio and / or amount of specific other monomers, it is possible to produce lenses having substantially lower tensile strength than that shown in formulations containing compounds of Formula 1 and Formula 2.

[0023] Silicon-free ingredients include N-vinylamide and methacrylate components.

[0024] The methacrylate component comprises hydroxybutyl methacrylate (HOB) and isobornyl methacrylate (IBM), and in some embodiments, is essentially composed of or consists of these. It is important that HOB and IBM are present in an amount of 8.5 to 16 weight percent and that the total amount of IBM is less than 5 weight percent. HOB and IBM are preferably present in the formulation in a ratio of 70:30 to 90:10. Preferably, the weight ratio of HOB to IBM is 85:15 to 90:10, and more preferably, the weight ratio is about 88:12.

[0025] The N-vinylamide component comprises N-vinyl N-methylacetamide (VMA). In some embodiments, the N-vinylamide component also comprises N-vinylpyrrolidone (NVP). When the N-vinylamide component comprises NVP and VMA, the ratio of NVP to VMA is preferably 70:30 to 30:70. In a preferred embodiment, the N-vinylamide component is essentially composed of NVP and VMA, and more preferably composed of these. Preferably, the N-vinylamide component is present in an amount of 33 to 37 weight percent.

[0026] Surprisingly, it was found that a specific ratio of HOB to IBM, with the inclusion of VMA and optionally NVP, produces lenses with desirable characteristics, particularly low tensile strength and low Young's modulus, compared to previous lenses formed using a combination of polysiloxane compounds of Formula 1 and Formula 2.

[0027] The N-vinylamide component is essentially composed of N-vinylpyrrolidone (NVP) and N-vinyl N-methylacetamide (VMA), and in some embodiments, is composed of these.

[0028] In some embodiments, the total amount of the compound of Formula 2, VMA and HOB is greater than 28 weight percent.

[0029] In a particularly preferred first embodiment, the contact lens formulation essentially comprises a silicone component of Formula 1 and Formula 2, wherein the ratio of Formula 1 to Formula 2 is 53:47 to 57:43. The N-vinylamide component essentially comprises NVP and VMA, wherein the ratio of NVP to VMA is 68:32 to 72:28. The methacrylate component essentially comprises HOB and IBM, wherein the ratio of HOB to IBM is 85:15 to 90:10. It is preferable that the silicone component is 45 to 55 weight percent of the formulation. It is more preferable that the methacrylate component is 10 to 20 weight percent of the formulation. It is even more preferable that the N-vinylamide component is 30 to 40 weight percent of the formulation.

[0030] In a particularly preferred second embodiment, the contact lens formulation essentially comprises a silicone component of Formula 1 and Formula 2, wherein the ratio of Formula 1 to Formula 2 is 73:27 to 77:23. The N-vinylamide component essentially comprises NVP and VMA, wherein the ratio of NVP to VMA is 32:68 to 28:72. The methacrylate component essentially comprises HOB and IBM, wherein the ratio of HOB to IBM is 85:15 to 90:10. It is preferable that the silicone component is 45 to 55 weight percent of the formulation. It is more preferable that the methacrylate component is 10 to 20 weight percent of the formulation. It is even more preferable that the N-vinylamide component is 30 to 40 weight percent of the formulation.

[0031] In a particularly preferred third embodiment, the contact lens formulation essentially comprises Formula 1, Formula 2, and Formula 3, wherein Formula 3 is present in an amount of less than 0.6 weight percent of the formulation and comprises a silicone component in which the ratio of Formula 1 to Formula 2 is 60:40 to 65:35. The N-vinylamide component essentially comprises VMA. The methacrylate component essentially comprises HOB and IBM, in which the ratio of HOB to IBM is 75:25 to 80:20. It is preferable that the silicone component is 45 to 55 weight percent of the formulation. It is more preferable that the methacrylate component is 5 to 15 weight percent of the formulation. It is even more preferable that the N-vinylamide component is 30 to 40 weight percent of the formulation.

[0032] Preferably, the formulation further comprises at least one of a photoinitiator, a thermal initiator; a crosslinking monomer; a UV blocker; and a coloring agent.

[0033] In another embodiment of the present invention, a silicone hydrogel contact lens comprising a polymerized reaction product of any prior embodiment is disclosed.

[0034] Silicone hydrogel contact lenses may have a tensile strength of 0.4 MPa to 1.0 MPa. Silicone hydrogel contact lenses generally have a tensile strength of 1.0 MPa or less, preferably 0.9 MPa or less. Silicone hydrogel contact lenses generally have a tensile strength of at least 0.4 MPa, more preferably at least 0.5 MPa. In at least some preferred embodiments, silicone hydrogel contact lenses have a tensile strength of 0.5 MPa to 0.9 MPa.

[0035] Silicone hydrogel contact lenses can have a sessile drop contact angle of less than 30 degrees, more preferably less than 25 degrees.

[0036] Silicone hydrogel contact lenses may have an equilibrium water content of 45 to 55 weight percent.

[0037] Silicone hydrogel contact lenses can have an oxygen permeability of more than 100 barrels, preferably more than 110 barrels, more preferably more than 120 barrels, particularly 110 to 140 barrels.

[0038] Silicone hydrogel contact lenses may have a Young's modulus of 1.1 MPa or less, preferably 1.0 MPa or less. The Young's modulus is preferably at least 0.3 MPa, more preferably at least 0.5 MPa. The preferred range is 0.5 MPa to 0.95 MPa.

[0039] Silicone hydrogel contact lenses may have a chord diameter of 13.5 to 15.5 mm and a base curve of 7.5 to 9.5 mm. A person skilled in the art knows other suitable chord diameters and base curves.

[0040] By using the above amounts of these components, it is possible to manufacture a lens having a good balance of properties and, in particular, appropriately low modulus and tensile strength.

[0041] When a specific selected silicone component is used, the applicant has confirmed that the balance of silicone-free methacrylate components is important to provide good properties to the resulting lens.

[0042] One way to demonstrate that a lens possesses good characteristics is to verify whether it satisfies the relative methacrylate-flexibility product. The applicant has confirmed that excellent lenses have a value greater than 1.25 for this product. These preferably have a value greater than 2.5, and more preferably greater than 5. Lenses having a product that satisfies this value exhibit a balance of good physical characteristics and, in particular, possess a good level of flexibility.

[0043] The relative methacrylate-flexibility product is measured as follows:

[0044] (Weight % HOB / Weight % IBM) * (Tensile strength / modulus)

[0045] These unitless parameters can enable a person of ordinary skill in the art to quickly evaluate whether a lens manufactured with the aforementioned identified major monomer will have good characteristics. Specific details for implementing the invention

[0046] details

[0047] The present invention describes a silicone hydrogel contact lens having excellent dimensional stability, being ophthalmologically acceptable, and capable of being manufactured without using volatile organic solvents or diluents in the formulation. The silicone hydrogel contact lens comprises a polymeric lens body that is a reaction product of a silicone hydrogel contact lens formulation or a polymerizable composition comprising a silicone component and a silicone-free component. The silicone component comprises two compounds, Formula 1 and Formula 2, or is essentially composed of these. It is important that the compound of Formula 1 and the compound of Formula 2 are present in a ratio of 50:50 to 77:23 and in a combined amount of 45 to 55 weight percent.

[0048] In this document, references to 'at least one' type of component refer to both a) a single component and b) a combination of two or more components of the same type.

[0049] Throughout this disclosure, references to the 'total amount' of a specific component (i.e., a combination of two or more components of the same type) in a polymerizable composition refer to the sum of the amounts of all components of the same type.

[0050] Unless otherwise indicated by the context, the following definitions of the cited terms provided below apply herein:

[0051] "Monomer" refers to any molecule capable of reacting with other identical or different molecules to form a polymer or copolymer. Accordingly, the term includes polymerizable prepolymers and macromonomers, and there are no size restrictions on monomers unless otherwise specified.

[0052] "Siloxane monomers" contain at least one Si-O group and are generally "monofunctional" or "polyfunctional," which means having one polymerizable group or two or more polymerizable groups, respectively. "Non-siloxane monomers" are monomers that do not contain any Si-O groups.

[0053] "Silicone components" are components or parts of a silicone hydrogel contact lens formulation composed entirely of siloxane monomers.

[0054] "Silicone-free ingredients" are components or parts of silicone hydrogel contact lens formulations composed entirely of non-siloxane monomers.

[0055] "N-vinylamide component" is a component or part of the silicone-free component of a silicone hydrogel contact lens formulation composed of at least one non-siloxane monomer having a vinyl group directly bonded to a nitrogen atom.

[0056] "Methacrylate component" is a component or part of a silicone-free component of a silicone hydrogel contact lens formulation composed of at least one non-siloxane monomer having a homopolymerizable methacrylate group.

[0057] "(Meth)acrylate-containing monomer" is any non-siloxane monomer having a homopolymerizable (meth)acrylate group (e.g., methyl methacrylate, etc.). A siloxane monomer having at least one polymerizable (meth)acrylate group is referred to herein as "(meth)acrylate-containing siloxane monomer". "(Meth)acrylate" includes both a methacrylate group and an acrylate group. If only methacrylate or acrylate is included, this will be explicitly stated.

[0058] "Consists of" means that the preparation or ingredient contains only the listed ingredients, compounds, or monomers.

[0059] "Essentially composed of" means that the formulation or component contains the listed compounds or monomers, but may also contain other monomers or compounds that fall within the defined range of that formulation or component, such as dimeric or polymeric impurities. These additional monomers or compounds may be present in amounts that do not affect the final lens formulation. Additional monomers or reactive substances may be present in amounts of less than 5%, 2%, 1%, 0.5%, or 0.1% based on the total amount of a specific formulation or component.

[0060] A "polymerizable composition" is a composition comprising a polymerizable component, wherein the composition has not yet been subjected to conditions that cause the polymerization of the polymerizable component. Therefore, the silicone hydrogel contact lens formulation is considered a polymerizable composition.

[0061] For polyorganosiloxane prepolymers and other polydisperse monomers, the term "molecular weight" as used herein refers to the absolute number average molecular weight M of the monomer. n It refers to the unit Dalton (Da) or g / mol. Number average molecular weight is generally determined using GPC with polystyrene standards. Additionally, number average molecular weight can be determined by identifying the number average molecular weight in the technical data sheet or specification sheet provided by the chemical supplier to the contact lens manufacturer.

[0062] In the present disclosure, if a value is given for a repeating group in a structural formula such as Formula 1, Formula 2, or Formula 3, it is an average value. A person skilled in the art will understand that this type of complex molecule contains a mixture of components.

[0063] As used herein, the terms “total formulation” or “total contact lens formulation” refer to all formulation components excluding diluents and / or solvents not included in the final polymeric contact lens material. Where a weight percentage of the components of the total formulation is provided, it should be understood as referring to a weight percentage of the components relative to the total weight of the formulation.

[0064] Throughout this disclosure, references to “examples,” “specific examples,” or similar phrases are intended to introduce features or characteristics of contact lenses, polymerizable compositions, or methods of manufacture (depending on the context), and these may be combined with any combination of previously described or subsequently described examples (i.e., features), unless the specific combination of features is mutually exclusive or otherwise indicated by the context.

[0065] Throughout this disclosure, where a series of lower and upper bound ranges are provided, all combinations of the provided ranges are considered as each combination is specifically listed. Also throughout this disclosure, where a series of values ​​is presented with a modifier preceding the first value, the modifier is intended to be implicitly present before each value in the series unless otherwise indicated by the context. For example, in the case of the values ​​listed above, the modifier "from" is intended to be implicitly present before the 50:50 ratio, and the modifier "to" is intended to be implicitly present before the 80:20 ratio.

[0066] As used herein, unless otherwise specified, ratio refers to weight ratio. As used herein, weight ratio refers to the ratio between the weight of the first component and the weight of the second component in a formulation.

[0067] A silicone hydrogel contact lens formulation comprising a silicone component; and a silicone-free component is disclosed herein.

[0068] The silicone component comprises a difunctional (meth)acrylate-containing siloxane monomer and a monofunctional methacrylate-containing siloxane monomer, or is essentially composed of these, or in some embodiments is composed of these.

[0069] The difunctional (meth)acrylate-containing siloxane monomer is represented by Chemical Formula 1:

[0070]

[0071] Here, R1 is selected from hydrogen or a methyl group; R2 is hydrogen or C 1-4 Selected from hydrocarbon groups; m represents an integer from 0 to 10; n represents an integer from 4 to 100; a and b represent integers greater than or equal to 1; a+b is 20-500; b / (a+b) is 0.01-0.22, and the composition of the siloxane unit includes a random composition.

[0072] The difunctional (meth)acrylate-containing siloxane monomer of Formula 1 may have an average molecular weight Mw of at least 8,000, 10,000, 12,000, or 15,000 Da. The difunctional (meth)acrylate-containing siloxane monomer of Formula 1 may have an average molecular weight Mw of less than 25,000, 20,000, 12,000, 11,000, 10,000, or 9,000 Da. Preferably, the difunctional (meth)acrylate-containing siloxane monomer has an average molecular weight Mw of 8,000 to 20,000 Da. In one preferred embodiment, the difunctional (meth)acrylate-containing siloxane monomer of Formula 1 has an average molecular weight Mw of 8,000 to 11,000 Da. In another preferred embodiment, the difunctional (meth)acrylate-containing siloxane monomer of Formula 1 has an average molecular weight Mw of 15,000 to 20,000 Da.

[0073] In certain embodiments, in the compound of Formula 1, R1 is selected from hydrogen or a methyl group; and R2 is hydrogen or C 1-4 Selected from hydrocarbon groups; m is 0; n represents an integer from 4 to 15; a represents an integer from 50 to 250, and b represents an integer from 5 to 50; the composition of the siloxane unit includes a random composition, wherein the ratio of a:b is 5:1 to 30:1, preferably 10:1 to 20:1.

[0074] R1 is preferably a methyl group. R2 is preferably H or a methyl group, more preferably a methyl group. Also, m is preferably 0. n is preferably 6 to 9.

[0075] In one preferred embodiment, a is 60 to 100, more preferably 70 to 80, and b is 4 to 8, more preferably 5 to 8. It is even more preferable that R1 is methyl, R2 is methyl, m is 0, and n is 7 to 8.

[0076] A particularly desirable difunctional (meth)acrylate-containing siloxane monomer has CAS registration number: 1216820-69-7.

[0077] In another preferred embodiment, a is 140 to 220, more preferably 150 to 200, and b is 8 to 15, more preferably 9 to 13. It is even more preferable that R1 is methyl, R2 is methyl, m is 0, and n is 7 to 8.

[0078] A method for preparing a compound of Formula 1 is described in U.S. Patent No. 8,129,442 (incorporated herein by reference).

[0079] The monofunctional methacrylate-containing siloxane monomer is represented by Chemical Formula 2:

[0080]

[0081] Here, n is an integer of about 10 to 25, preferably 13 to 18.

[0082] The monofunctional methacrylate-containing siloxane monomer of Formula 2 has an average molecular weight of less than 2,000, preferably less than 1,800 Da, and greater than 800, preferably greater than 1,000 Da. In a more specific example, the monofunctional methacrylate-containing siloxane monomer may have an average molecular weight of 1,000 to 1,800 Da.

[0083] Preferably, the monofunctional methacrylate-containing siloxane monomer has the CAS registration number 697234-76-7.

[0084] The siloxane monomer of Chemical Formula 2 is described in U.S. Patent No. 6,310,169 (incorporated herein by reference).

[0085] The compound of Formula 1 and the compound of Formula 2 are present in a weight ratio of 50:50 to 77:23. In one preferred embodiment, the weight ratio of the compound of Formula 1 to the compound of Formula 2 is 53:47 to 77:23. In some specific embodiments, the weight ratio is 52:48 to 58:42. In some specific embodiments, the weight ratio is 60:40 to 65:35. In some specific embodiments, the weight ratio is 70:30 to 77:23. In some specific embodiments, the weight ratio is about 55:45, about 63:37, or about 75:25.

[0086] The compound of Formula 1 and the compound of Formula 2 are present in a combined amount of 45 to 55 weight percent.

[0087] In an additional embodiment, the silicon component comprises an additional silicon compound, which is a monofunctional (meth)acrylate-containing siloxane monomer of Formula 3:

[0088]

[0089] Here, m represents an integer from 3 to 12, n represents an integer from 1 to 10, and R 1 is selected from alkyl groups having 1 to 4 carbon atoms, and R of Formula 3 2 and R 3 Each is independently selected from a hydrogen atom or a methyl group.

[0090] In some embodiments, in the compound of Formula 3, m is 4 and n is 1. R 1 is a butyl group, and R 2 is H, and R 3 It is more preferable that it be a methyl group.

[0091] Where the compound of Formula 3 is present, it is used in an amount of less than 1 weight percent of the total contact lens formulation, preferably less than 0.8 weight percent, and more preferably less than 0.6 weight percent. In one preferred embodiment of the formulation, the silicone component is essentially composed of Formula 1, Formula 2, and Formula 3, and preferably composed of these.

[0092] In some embodiments, the weight percentage of the silicone component is greater than 48%, 48.5%, or 49%. In some embodiments, the weight percentage of the silicone component is less than 53%, 52.5%, 52%, 51.5%, 51%, or 50.5%. In some embodiments, any one of the lower limits of the weight percentage of the silicone component is combined with any one of the upper limits of the weight percentage of the silicone component. For example, the silicone component may be present in the formulation at 48% (wt / wt) to 53% (wt / wt), preferably 48% to 51%.

[0093] In another preferred embodiment, the amount of the compound of Formula 2 is preferably greater than 12 weight percent of the total composition. It is more preferable that the amount of the compound of Formula 2 is less than 25 weight percent. For example, the compound of Formula 2 may be present in the formulation at 12 to 25% (wt / wt).

[0094] In another preferred embodiment, the amount of the compound of Formula 1 is preferably less than 38 weight percent. It is more preferable that the amount of the compound of Formula 1 is greater than 26 weight percent. For example, the compound of Formula 1 may be present in the formulation at 26 to 38% (wt / wt).

[0095] It is particularly desirable that the amount of the compound of Formula 2 is greater than 12 weight percent and the amount of the compound of Formula 1 is less than 38 weight percent.

[0096] In addition, it can be understood that the silicone component of the present formulation does not contain a hydroxy-functionalized siloxane compound, does not contain TRIS, or does not contain both.

[0097] The silicon-free component includes an N-vinylamide component (c); and a methacrylate component (d).

[0098] The N-vinylamide component includes N-vinyl N-methylacetamide (VMA). The N-vinylamide component optionally further includes N-vinylpyrrolidone (NVP). The N-vinylamide component is essentially composed of NVP and VMA, and preferably, it is more preferable that it is composed of these.

[0099] In one preferred embodiment, when the N-vinylamide component comprises both NVP and VMA, the ratio of NVP to VMA is 70:30 to 30:70. In some embodiments, the ratio is about 70:30. In some embodiments, the ratio is about 30:70. In a more specific example, the polymerizable composition has a weight ratio of the total amount of N-vinylamide component to the total amount of (meth)acrylate-containing siloxane monomers (i.e., monofunctional and bifunctional (meth)acrylate-containing siloxane monomers) of about 40:60 to 45:55. It is more preferable that the ratio is 41:59 to 42:58.

[0100] In some embodiments, the weight percentage of the N-vinylamide component is greater than 34% or 34.5%. In some embodiments, the weight percentage of the N-vinylamide component is less than 40%, 39%, 37%, 36%, or 35.5%. In some embodiments, any one of the lower limits of the weight percentage of the N-vinylamide component is combined with any one of the upper limits of the weight percentage of the N-vinylamide component. In some embodiments, the weight percentage of the N-vinylamide component is 34.5% to 35.5%.

[0101] In one preferred embodiment, the N-vinylamide component is essentially composed of VMA, preferably. In a more specific example, the polymerizable composition has a weight ratio of the total amount of the N-vinylamide component to the total amount of (meth)acrylate-containing siloxane monomers (i.e., monofunctional and difunctional (meth)acrylate-containing siloxane monomers) of about 40:60 to 45:55. The ratio is more preferably 44:56 to 45:55.

[0102] If the N-vinylamide component is essentially composed of VMA, or if it is composed of VMA, the weight percentage of the N-vinylamide component is greater than 35% or 38%. The weight percentage of the N-vinylamide component is less than 40% or 39%. In some embodiments, any one of the lower limits of the weight percentage of the N-vinylamide component is combined with any one of the upper limits of the weight percentage of the N-vinylamide component. In some embodiments, the weight percentage of the N-vinylamide component is 38% to 39%.

[0103] In another specific example, the total amount of the compound of Formula 2 and the N-vinylamide component is at least 47 weight percent, preferably at least 50 weight percent. The total amount of the compound of Formula 2 and the N-vinylamide component is less than 70 weight percent, preferably less than 60 weight percent.

[0104] The methacrylate components include hydroxybutyl methacrylate (HOB) and isobornyl methacrylate (IBM). It is important that HOB and IBM are present in the formulation in an amount of 8.5 to 16 weight percent, and that the total amount of IBM is less than 5 weight percent. Preferably, HOB and IBM are present in the formulation in a ratio of 70:30 to 90:10.

[0105] The methacrylate component (d) comprises hydroxybutyl methacrylate (HOB) and isobornyl methacrylate (IBM), and in some embodiments, is essentially composed of these, and in some embodiments, is composed of these. In some embodiments, the ratio of HOB to IBM is greater than 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, or 87:13. In some embodiments, the ratio of HOB to IBM is less than 90:10, 89.5:10.5, 89:11, or 88.5:11.5. In some embodiments, any one of the lower limits of the ratio of HOB to IBM is combined with any one of the upper limits of the ratio of HOB to IBM. In some embodiments, the ratio of HOB to IBM is 85:15 to 90:10 or about 88:12. In some embodiments, hydroxybutyl methacrylate and isobornyl methacrylate are present in the formulation in a weight percent greater than 11, 12, or 13 weight percent. In some embodiments, hydroxybutyl methacrylate and isobornyl methacrylate are present in the formulation in a weight percent less than 16. In some embodiments, either of the lower limits of HOB and IBM is combined with either of the upper limits of HOB and IBM. Preferably, the total amount of HOB and IBM is 13.6 to 16 weight percent.

[0106] In an alternative embodiment, the weight ratio of HOB to IBM is preferably 75:25 to 80:20, more preferably about 77:23. In this embodiment, the total amount of HOB and IBM is preferably less than 10 weight percent.

[0107] Other silicone-free methacrylate-containing monomers are known in the art and may be present in contact lens formulations. Exemplary silicone-free methacrylate-containing monomers include methyl methacrylate (MMA), tert-butyl methacrylate (tBMA), 2-hydroxyethyl methacrylate (HEMA), ethylene glycol methyl ether methacrylate (EGMA), and combinations thereof. A preferred additional silicone-free methacrylate-containing monomer is methyl methacrylate (MMA).

[0108] These additional methacrylate-containing monomers are preferably present in a total amount of less than 5 weight percent, more preferably less than 3 weight percent, and even more preferably less than 1 weight percent of the contact lens formulation, and much more preferably in small amounts as defined above, wherein the methacrylate component essentially consists of HOB and IBM. It is particularly preferable that there are no other methacrylate-containing monomers.

[0109] In a specific example, the polymerizable composition may have a weight ratio of the total amount of the compound of Formula 2 to the non-siloxane methacrylate-containing monomer greater than 0.9:1, preferably greater than 1:1.

[0110] In another specific example, the total amount of monofunctional (methacrylate-containing non-silicon and siloxane monomers) is greater than 26 weight percent in bulk, preferably greater than 30 weight percent.

[0111] Generally, the formulation further comprises one or more additional components common to contact lens formulations. Suitable additional components include photoinitiators, thermal initiators, crosslinking agents, UV blockers, and colorants.

[0112] The polymerizable composition may further comprise at least one non-siloxane crosslinking agent. As used herein, "crosslinking agent" is any compound having a molecular weight of less than about 2,000 Da having two or more ethylenically unsaturated groups. Thus, the crosslinking agent can react with two or more functional groups on the polymer chain to crosslink one polymer to another polymer. In the formulations of the present invention, TAIC is particularly preferred as the crosslinking agent.

[0113] The crosslinking agent is preferably used in an amount of 0.03 to 0.2 weight percent of the contact lens formulation.

[0114] The composition may additionally include one or more coloring agents. A preferred coloring agent is a reactive coloring agent, specifically a coloring agent identified as a "Reactive Blue" dye.

[0115] The composition may additionally include one or more UV blockers.

[0116] Contact lenses may be manufactured from the polymerizable composition described herein using curing and other processing methods known in the art, such as casting, spin casting, injection molding, turning after forming a polymerized rod, etc. In a specific example, the polymerizable composition is cast between molds formed of a thermoplastic polymer. The thermoplastic polymer is generally a non-polar material, such as polypropylene, but a polar mold material, such as ethylene vinyl alcohol, is also used in the art. Briefly, a first mold member, referred to as the "female mold member," which defines the front surface of the contact lens, is filled with an amount of the polymerizable composition sufficient to form a homopolymeric lens body. A second mold member, referred to as the "male mold member," which defines the rear (i.e., contacting the eye) surface of the contact lens, is joined to the female mold member to form a mold assembly having a lens-shaped cavity with an amount of the polymerizable composition between them.

[0117] The polymerizable composition within the contact lens mold assembly is polymerized using any suitable curing method. Generally, the polymerizable composition is exposed to heat or ultraviolet (UV) light in an amount sufficient to polymerize it. In the case of UV-curing, also known as photopolymerization, the polymerizable composition generally comprises a photoinitiator such as benzoin methyl ether, 1-hydroxycyclohexylphenyl ketone, Darocure, or Irgacur (available from Ciba Specialty Chemicals). A photopolymerization method for contact lenses is described in U.S. Patent No. 5,760,100, incorporated herein by reference. In the case of thermal-curing, also known as heat curing, the polymerizable composition generally comprises a thermal initiator. Exemplary thermal initiators include 2,2'-azobis(2,4-dimethylpentanenitrile) (VAZO-52), 2,2'-azobis(2-methylpropanenitrile) (VAZO-64), and 1,1'-azobis(cyanocyclohexane) (VAZO-88). A contact lens mold assembly containing a contact lens formulation is cured by exposing the contact lens mold assembly to heat or UV light for a time ranging from about 1 hour to about 5 hours. Additional thermal polymerization methods for contact lenses are described in U.S. Publication No. 2007 / 0296914 and U.S. Patent No. 7,854,866, incorporated herein by reference.

[0118] Upon completion of curing, the polymerized material between the mold members of the mold assembly takes the shape of a contact lens and is referred to herein as a "polymeric lens body." The male and female mold members are demolded, i.e., separated, and the polymeric lens body is removed from the mold member to which it is attached, i.e., lens separated. These processes are referred to as demolding and lens separation, respectively, and various such methods are known to those skilled in the art. In some methods, the demolding and lens separation process may comprise a single process step; for example, if a liquid is used to separate the mold, this also removes the polymeric lens body from the mold. In other methods, for example, if a dry demolding process is used, the polymeric lens body generally remains on one of the mold members and lens is separated in a subsequent process step. Lens separation may also be a wet or dry process. In one example, lens separation is performed by a "float-off" method in which the mold member to which the polymeric lens body is attached is immersed in water. The water may be heated optionally (e.g., up to about 100°C). Generally, the polymeric lens body is float-separated from the mold member within about 10 minutes. Dry lens separation may be performed manually, for example, by using tweezers to remove the polymeric lens body from the mold member, or may be removed using an automated mechanical process as described in U.S. Patent No. 7,811,483 (incorporated herein by reference). Additional demolding and lens separation methods for silicone hydrogel contact lenses are described in U.S. Publication No. 2007 / 0035049 (incorporated herein by reference).

[0119] After separating the lens, the polymeric lens body is washed to remove unreacted or partially reacted components from the polymeric lens body and to hydrate the polymeric lens body. For example, the contact lens may be exposed to an organic solvent, such as ethanol, isopropyl alcohol, industrial methylated spirits, etc., or water, or a mixture thereof. An exemplary washing method is described in U.S. Patent Publication No. 2007 / 0296914 (incorporated herein by reference) and Example 1 below.

[0120] After washing, the hydrated polymeric lens bodies are placed in a blister package, glass vial, or other suitable container, generally referred to herein as a “package.” A packaging solution is also added to the container, and the packaging solution is typically a buffered saline solution, such as phosphate- or borate-buffered saline. The packaging solution may optionally contain additional components, such as comfort agents, hydrophilic polymers, surfactants, or other additives to prevent the lens from sticking to the container, etc. The package is sealed, and the sealed polymeric lens bodies are sterilized by autoclaving. The final product is a sterile, packaged ophthalmologically acceptable contact lens.

[0121] In any of the examples described above, the contact lens may be characterized by one or more of the following properties, as described in detail below: contact angle, oxygen permeability, tensile strength, Young's modulus, and equilibrium water content.

[0122] In any of the examples described below, the contact lens may have a contact angle of approximately 30° or less than 25°, where the contact angle is the static advancing contact angle as determined using the Cecil droplet method. To determine the contact angle of the contact lens surface, the contact lens to be tested is immersed in phosphate buffer solution (PBS) for at least 12 hours. Using tweezers with rubber tips, the lens is removed from the PBS and shaken to remove excess water. A 4 mm diameter section of each lens is cut with a lens cutter. The surface of the contact lens section to be tested is placed upside down on a microscope lens wipe and wiped dry by gently dragging the lens section across the wipe with tweezers with rubber tips until no liquid absorbed by the wipe is observed. The lens section is placed on a microscope slide so that it lies flat with the wiped surface facing upward. Measurements are taken immediately to prevent the lens section from drying out (as evidenced by deformation of the lens section). On the Kruess DSA-100, turn on the Drop Shape Analysis program and select the "Cecil Droplet (VCA eq)" method with the following settings: Camera Tilt = +2; 100 µL syringe with a straight needle; Dispensing Solution = Purified Water; Dispensing Volume = 0.75 µL; Dispensing Rate = 7.5 µL / min; and Dispensing Mode = Volume. Place the microscope slide on the sample stage so that the longer side of the lens section is perpendicular to the camera. Move the syringe to align with the view screen and adjust the image until it reaches a maximum in the center window. Dispense water onto the lens. Capture an image of the droplet between 10 and 15 seconds after dispensing the water. Select the calculation method based on the contact angle as follows: <30° = Circular Fit; 30°–130° = Tangent Method-1; >130° = Tangent Method-2. The average contact angle measurement of the five lens sections is considered to be the contact angle for a specific surface of the contact lens (i.e., the back or front).

[0123] For oxygen permeability, the Dk values ​​provided in the following examples were determined using a Rehder 201T oxygen permometer / polarography cell according to the polarography method described in Section 4.4.3 of ISO18369-4:2017.

[0124] In any of the examples described below, the contact lens may have a Young's modulus (i.e., tensile modulus) of at least 0.3 MPa or 0.5 MPa, to 0.95 MPa, 1.0 MPa, or 1.1 MPa. In a preferred embodiment, the contact lens has a Young's modulus of 0.3 MPa to 1.1 MPa, preferably 0.5 to 0.95 MPa.

[0125] The contact lens has a tensile strength of 1.0 MPa or less, preferably 0.9 MPa or less. The contact lens generally has a tensile strength of at least 0.4 MPa, more preferably at least 0.5 MPa. A preferred embodiment of the contact lens has a tensile strength of 0.5 MPa to 0.9 MPa.

[0126] The modulus, elongation, and tensile strength values ​​reported herein were determined using an Instron Model 3342, 3343, or 5944 mechanical testing system (Instron Corporation, Norwood, Massachusetts, USA) and Bluehill Materials testing software, using a custom-made rectangular contact lens cutting die with a 4 mm spacing to prepare rectangular sample strips. The modulus was determined in a chamber with at least 70% relative humidity. Before testing, the lenses were immersed in phosphate buffered solution (PBS) for at least 10 minutes. A central strip of the lens was cut using the cutting die while holding the concave side of the lens facing upward. The thickness of the strip was determined using a calibrated gauge (Rehder electronic thickness gauge, Rehder Development Company, Castro Valley, California, USA). The strip was loaded onto the grips of the calibrated Instron device using tweezers so that the strip was fitted across at least 75% of the grip surface of each grip. A test method designed to determine the mean and standard deviation of the maximum load (N), tensile strength (MPa), strain at maximum load (% elongation), and tensile modulus (MPa) was executed, and the results were recorded.

[0127] In any of the examples described above, the contact lens may have an equilibrium water content (EWC) of at least about 30 wt%, 40 wt%, or 45 wt% and at most about 50 wt%, 55 wt%, 60 wt%, or 70 wt%. For example, the contact lens may have an EWC of 40 to 60 wt%. To measure the EWC, excess surface moisture is wiped off from the lens and the lens is weighed to obtain the hydrated weight. The lens is dried in an oven at 105°C and weighed. The weight difference is determined by subtracting the weight of the dried lens from the weight of the hydrated lens. The weight% EWC of the lens is = (weight difference / hydrated weight) x 100. In a specific example, the contact angle is ≤30° and the equilibrium water content is most preferably at least 45 wt% and at most 55 wt%.

[0128] As can be seen from the disclosure of the application as a whole, including the claim structure and specific examples, the exemplary components of the polymerizable composition disclosed herein are generally combined in the embodiments of the present invention. For example, a person skilled in the art will know that the polymerizable composition of the present invention advantageously comprises the exemplary monofunctional (meth)acrylate-containing siloxane monomer disclosed herein in combination with the exemplary difunctional (meth)acrylate-containing siloxane monomer disclosed herein, in combination with the exemplary N-vinylamide component disclosed herein, and in combination with the exemplary (meth)acrylate component disclosed herein.

[0129] As demonstrated by specific examples, it has been found that a combination of the preferred monofunctional methacrylate-containing siloxane monomer, difunctional (meth)acrylate-containing siloxane monomer, N-vinylamide component, and methacrylate-containing monomer of the present invention provides advantageous properties, such as reduced tensile strength, to the contact lenses of the present invention.

[0130] Examples

[0131] The following examples illustrate specific aspects and advantages of the present invention and should not be understood as being limited thereto. The reactants used in the examples are described in detail in Table 1, the specific amounts of each component used are presented in Table 2 as weight percentages of the total formulation, the ratios of the components and the total sum are shown in Table 3, and the characteristics are presented in Table 4.

[0132] The silicone hydrogel lenses of Examples 1 to 3 and Comparative Examples were prepared according to the following method.

[0133] Compounds or monomers were all mixed and stirred to form a polymerizable composition or a silicone hydrogel contact lens formulation.

[0134] The formulation was placed in a contact lens mold.

[0135] The lenses were cured by using ultraviolet light for about 1 hour (Examples 1 and 2 and Comparative Example) or by using heat for about 5 hours (Example 3). A person skilled in the art knows a suitable method for curing contact lens formulations.

[0136] The cured polymer was removed from the contact lens mold and washed to remove unreacted material by contacting it with an organic solvent, water, or a combination thereof. Then, the washed contact lenses were placed in a package and sterilized in an autoclave to provide sterile packaged contact lenses. The contact lenses of all examples and comparative examples were transparent and flexible, and also had good moisture wettability.

[0137] Table 1

[0138]

[0139] Table 2

[0140]

[0141] Table 3

[0142]

[0143] Table 4

[0144]

[0145] In Table 3, "(Chemical Formula 2)" represents the general structure of the compound of Chemical Formula 2 in this description, and Si-2 is a specific embodiment within Chemical Formula 2.

[0146] It is surprising that the specific selection of non-silicon monomers and the HOB to IBM ratio can significantly reduce the tensile strength of the resulting lens. The lens of the present invention possesses other advantageous features observed in lenses of the prior art formed using the same combination of siloxane monomers, such as high Dk and a good Cecil droplet contact angle.

[0147] While the disclosure of this application refers to specific exemplary examples, it should be understood that these examples are presented as examples and not as limitations. The intent of the foregoing detailed description is to discuss exemplary examples, but to be interpreted as encompassing all variations, alternatives, and equivalents of the examples that may fall within the spirit and scope of the invention as defined by additional disclosures.

[0148] Several publications and patents have been cited in the foregoing. The full text of each cited publication and patent is incorporated herein by reference.

Claims

Claim 1 A silicone hydrogel contact lens formulation comprising (i) a silicone component; and (ii) a silicone-free component, wherein the silicone component is (a) a compound of Formula 1 (Here, R1 is selected from hydrogen or a methyl group; R2 is hydrogen or C 1-4 Selected from hydrocarbon groups; m represents an integer from 0 to 10; n represents an integer from 4 to 100; a and b represent integers greater than or equal to 1; a+b is 20 to 500; b / (a+b) is 0.01 to 0.22, and the composition of the siloxane unit includes a random composition); and (b) a compound of Formula 2 (wherein n is 10 to 25) comprising, wherein the compound of Formula 1 and the compound of Formula 2 are present in the formulation in a ratio of 50:50 to 77:23 and a combined amount of 45 to 55 weight percent; the silicone-free component comprises an N-vinylamide component (c); and a methacrylate component (d), wherein the N-vinylamide component (c) comprises N-vinyl N-methylacetamide (VMA); and the methacrylate component (d) comprises hydroxybutyl methacrylate (HOB) and isobornyl methacrylate (IBM), wherein hydroxybutyl methacrylate and isobornyl methacrylate are present in the formulation in an amount of 8.5 to 16 weight percent and the total amount of IBM is less than 5 weight percent. Claim 2 A preparation according to claim 1, wherein the total amount of the compound of formula 2, VMA, and HOB exceeds 28 weight percent. Claim 3 A formulation according to claim 1 or 2, further comprising at least one of a photoinitiator; a thermal initiator; a crosslinking monomer; a UV blocker; and a coloring agent. Claim 4 A formulation according to claim 1 or 2, wherein the N-vinylamide component (c) comprises VMA and N-vinylpyrrolidone (NVP). Claim 5 A preparation according to claim 1 or 2, wherein the N-vinylamide component is present in an amount of 33 to 39 weight percent. Claim 6 A formulation according to claim 1 or 2, wherein the ratio of HOB to IBM is 85:15 to 90:

10. Claim 7 A preparation according to claim 1 or 2, wherein the ratio of the compound of Formula 1 to the compound of Formula 2 is 55:45 to 75:

25. Claim 8 A formulation according to paragraph 1 or 2 in which the ratio of HOB to IBM is 88:

12. Claim 9 A formulation according to claim 1, wherein the ratio of formula 1 to formula 2 is 53:47 to 57:43; the N-vinylamide component is essentially composed of NVP and VMA, wherein the ratio of NVP to VMA is 68:32 to 72:28; and the methacrylate component is essentially composed of HOB and IBM, wherein the ratio of HOB to IBM is 85:15 to 90:

10. Claim 10 In claim 1, the silicone component is Chemical Formula 1, Chemical Formula 2 and Chemical Formula 3: (Here, m represents an integer from 3 to 12, n represents an integer from 1 to 10, and R 1 is selected from alkyl groups having 1 to 4 carbon atoms, and R of Formula 3 2 and R 3 A formulation essentially composed of (each independently selected from a hydrogen atom or a methyl group), wherein Formula 3 is present in an amount of less than 0.6 weight percent of the formulation; the ratio of Formula 1 to Formula 2 is 60:40 to 65:35; the N-vinylamide component is essentially composed of VMA; and the methacrylate component is essentially composed of HOB and IBM, wherein the ratio of HOB to IBM is 75:25 to 80:

20. Claim 11 A silicone hydrogel contact lens comprising a polymerized reaction product of any one of claims 1, 2, 9 and 10. Claim 12 In claim 11, a silicone hydrogel contact lens having a tensile strength of 0.4 MPa to 1 MPa. Claim 13 In claim 11, a silicone hydrogel contact lens having a sessile drop contact angle of less than 30 degrees. Claim 14 In claim 11, a silicone hydrogel contact lens having an equilibrium water content of 45% to 55% by weight. Claim 15 In claim 11, a silicone hydrogel contact lens having an oxygen permeability of 110-140 barrels. Claim 16 In claim 11, a silicone hydrogel contact lens having a Young's modulus of 0.3 MPa to 1.1 MPa. Claim 17 In claim 11, a silicone hydrogel contact lens having a chord diameter of 13.5 to 15.5 mm and a base curve of 7.5 to 9.5 mm.

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