AU2012200844B2 - Novel PDMS-PVP block copolymers - Google Patents

Abstract

A (meth)acrylated polyvinylpyrrolidone of the general structure depicted below, suitable for use as a polymerizable wetting agent in a contact lens formulation: H - R3 O R2n R4 wherein R, is hydrogen or CI-8-alkyl, preferably H; R2 is pyrrolidinone; n = 1 - 10,000; R3 is a divalent aliphatic linkage chain containing up to 8 carbon atoms and up to 2 oxygen, sulfur, and/or nitrogen atoms in the linkage chain, such as C(CH 3)2-CH2-CH2, C(CH 3)2, S-(CH 2 )2, C(CH 3)-O C(=0)-NH-(CH 2)2, C;(CH3)-CH 2-CH2-O-C(=0)-NH-(CH 2)2, or S-(CH 2)2-O-C(=0)-N H-(CH 2)2; and R4 is hydrogen or C1.s-alkyl, such as CH3.

Description

AUSTRALIA Patents Act COMPLETE SPECIFICATION (ORIGINAL) Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Name of Applicant: DSM IP Assets B.V. Actual Inventor(s): James P. Parakka, Robert S. Ward, Keith R. McCrea Address for Service and Correspondence: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: NOVEL PDMS-PVP BLOCK COPOLYMERS Our Ref: 934983 POF Code: 474902/464219 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): - 1- ]A NOVEL PDMS-PVP BLOCK COPOLYMERS FIELD OF THE INVENTION The present application is a divisional application from Australian patent application No. 2008224989, the entire disclosure of which is incorporated herein by reference. [00011 This invention relates to polymerizable poly(N-vinyl-2-pyrrolidone) (PVP) and amphipathic copolymers containing polydimethylsiloxane (PDMS) and polyvinylpyrrolidone. Such copolymers are of particular use as components in biomedical devices such as ophthalmic applications and wound care. BACKGROUND OF THE INVENTION [00021 N-vinyl-2-pyrrolidone and its polymer, poly(N-vinyl-2-pyrrolidone) (PVP), is a water soluble and biocompatible polymer that has been widely used for a range of commercial applications including for tablet binding, hair fixation, wetting agents in ophthalmic lens formulations, membranes, adhesives, hydrophilic coatings, etc. Several methods for preparation of functionalized polyvinylpyrrolidones have been reported, for instance using azo radical initiators in the presence of chain transfer agents (e.g., mercaptoethanol, isopropanol, isopropoxyethanol, mercaptoethylamine, mercaptopropionic acid). See e.g. US 5,135,297 (SURFACE COATING OF POLYMER OBJECTS); US 6,756,449 B2 (ANB BLOCK COPOLYMERS CONTAINING POLY (VINYL PYRROLIDONE) UNITS, MEDICAL DEVICES, AND METHODS); and US 2005/0119404 A l (PROCESS FOR THE PREPARATION OF AMPHIPHILIC POLY (N-VINYL-2-PYRROLIDONE) BLOCK COPOLYMERS). The disclosure of each of these documents is included herein by reference. [0003] It is desirable in some cases to build functionality into the PVP to prepare materials that will be retained permanently in the final functional polymer device without leaching of the PVP component during use. For instance, (meth)acrylated or (meth)acrylamide functionalized PVP derivatives will find utility in contact lens compositions. In practice, during irradiation or thermal polymerization of the contact lens mix, the functional PVP will be covalently bonded into the crosslinked network and provide a non-leachable wettable ophthalmic lens. 100041 Copolymers that incorporate silicone (PDMS) blocks and hydrophilic moieties such as PVP, poly(dialkylacrylamide) (e.g. polydimethyacrylamide, polyN-isopropylacrylamide and the like), and polyalkyleneglycol should compatibilize the hydrophobic and hydrophilic components of a contact lens formulation generating optically clear and functional lenses. These copolymers would be useful as 2 active components in applications such as silicone hydrogel lenses. In addition, amphiphilic moieties will also find use in lens care solutions targeted for specific types of contact lens. Besides ophthalmic and lens care solutions, other applications for the amphipathic block copolymers include use in tissue engineering, transdermal implants and wound dressings, industrial adhesives, sealants, surface protecting agents, drug release agents and other biomedical applications. A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims. Throughout the description and claims of the specification, the word "comprise" and variations of the word, such as "comprising" and "comprises", is not intended to exclude other additives, components, integers or steps. SUMMARY OF THE INVENTION [00051 The present invention discloses methods for preparation of functionalized polyvinylpyrrolidone (PVP) with polymerizable functions and also of novel amphipathic polydimethylsiloxane - PVP copolymers. The block copolymers of the present invention are particularly useful as biomaterial components in biomedical devices. Preferred embodiments of materials disclosed in this invention provide improved wettability, lubricity, and material compatibility to the biomedical device (e.g. an ophthalmic lens). In one aspect, the present invention provides a (meth)acrylated polyvinylpyrrolidone of the general structure depicted below, suitable for use as a polymerizable wetting agent in a contact lens formulation: H R3,O [ R2J-nR wherein R, is hydrogen or CI.

8 -alkyl, preferably H; R 2 is pyrrolidinone; n = I - 10,000; R 3 is a divalent aliphatic linkage chain containing up to 8 carbon atoms and up to 2 oxygen, sulfur, and/or nitrogen atoms in the linkage chain, such as C(CH 3

)

2

-CH

2

-CH

2 , C(CH 3

)

2 , S-(CH 2

)

2 , C(CH 3

)

2 -- C(=0)-NH

(CH

2

)

2 , C;(CH 3

)

2

-CH

2

-CH-O-C(=O)-NH-(CH

2

)

2 , or S-(CH 2

)

2

-O-C(=O)-NH-(CH

2

)

2 ; and R 4 is hydrogen or C 18 -alkyl, such as CH 3

.

2a In another aspect, the present invention provides a (meth)acrylamide functionalized polyvinylpyrrolidone of the general structure depicted below, suitable for use as a polymerizable wetting agent in a contact lens formulation: R1 -0 H'I .2R3,H" -n R4 wherein R, is hydrogen or Cl-8-alkyl; R2 is pyrrolidinone; n = 1 -10,000; R3 is a divalent aliphatic linkage chain containing up to 8 carbon atoms and up to 2 oxygen, sulfur, and/or nitrogen atoms in the linkage chain, such as S-(CH 2 )m wherein m is 1-6; and R 4 is hydrogen or CI 8 -alkyl, such as CH 3 . [00061 Further aspects of this invention provide an amphipathic diblock copolymer compound having the following structure:

CH

3

CH-

3 - C R3 Si, .Si- X -H R14 X C ., CH R2 L . a - b O- -cCN R 4 -d

R

1 = alkyl, alkoxy; R 2 = (CH2)n; (CH2)m-O(CH2)n, m and n can be between 1-16; a = 1-200; b = 1-6; c = 1-6; d = 1-10000; X = 0, NH, S; R 3 = H, CH3; R4 = pyrrolidinone, C(=0)OH, C(=O)OAlkyl, Ph, substituted Ph, C(=0)NH2, C(=O)N(alkyl)2, OC(=O)CH3, OH, C(=O)-oxylethylphosphorycholine 3 In typical specific embodiments of that diblock copolymer, Ri is butyl, "a" ranges from 2 to 50, R 2 is (CH 2

)

3 or (CH 2

)

3

-O-(CH

2

)

2 , "b" is 1, X is 0 or NH, R 3 is H, R 4 is pyrrolidinone, and "d" ranges from 10 to 10,000. These novel amphipathic diblock copolymers may be formulated for use: as a lens care component for contact lenses, e.g., silicone hydrogel lenses; as an oxygen permeable and wettable backing material for a wound healing device; as a scaffold for tissue engineering; or as a component for controlled drug release. [0007] Another generic embodiment of this invention is an amphipathic triblock copolymer compound having the following structure: H H3 C31 CH 3 [ CH, R 3 H H X R2 R X 3 . R4 d CN . cO b 3 - b 0 cCN R 4 - d R2 = (CH2)n; (CH2)m-O(CH2)n, m and n can be between 1-16; a = 1-200; b = 1-6; c = 1-6; d = 1-10000; X = 0, NH, S; R 3 = H, CH3; R 4 = pyrrolidinone, C(=0)OH, C(=O)OAlkyl, Ph, substituted Ph, C(=O)NH2, C(=O)N(alkyl)2, OC(=O)CH3, OH, C(=O)-oxylethylphosphorycholine In typical specific embodiments of that triblock copolymer, R 2 is (CH 2

)

3 or (CH2)3-0-(CIIH2)2,

R

3 is H, R 4 is pyrrolidinone, X is 0 or NH, "a" ranges from 2 to 50, "b" is 1, "c" is 2, and "d" ranges from 10 to 10,000. These novel amphipathic triblock copolymers may bc formulated for usc: as a lens care component for contact lenses, e.g., silicone hydrogel lenses; as an oxygen permeable and wettable backing material for a wound healing device; as a scaffold for tissue engineering; or as a component for controlled drug release. [00081 Yet another generic embodiment of the present invention is an amphipathic diblock copolymer compound bearing polymerizable functionality, and having this structure: CH3 CH 3 0 RR1 X 3

CH

3 b O cCN [ R 4 d R 6 R1 = alkyl, alkoxy; R 2 = (CH2)n; (CH2)m-O(CH2)n, m and n can be between 1-16; a = 1-200; b = 1-6; c = 1-6; d = 1-10000; X = 0, NH, S; Y = 0, NH; R3 = H, CH3; R 4 = pyrrolidinone, C(=O)OH, C(=O)OAlkyl, Ph, substituted Ph, C(=O)NH2, C(=O)N(alkyl)2, OC(=0)CH3, OH, C(=0)-oxylethylphosphorycholine; R5 = C(CH 3

)

2 -0-CH2-CH 2 , C(CH 3

)

2 , S-(CH 2

)

2 , C(CH 3

)

2 -0-C(=O)-NH-(CH 2

)

2 ,

C(CH

3

)

2 -0-CH 2

-CH

2 -0-C(=O)-NH-(CH2) 2 , S-(CH 2

)

2 -0-C(=0)-NH-(CH 2

)

2 ; Re = H or CH3 4 In typical speci Fic embodiments of that diblock copolymer, R, is butyl, "a" ranges from 2 to 50, R 2 is (CH 2

)

3 or (CH 2

)-O-(CH

2 h, "b" is 1, X is 0 or NI, R 3 is H, R 4 is pyrrolidinone, "d" ranges from 10 to 10,000, R5 is C(CH 3

)

2 -0-CH 2

-CH

2 or C(CH 3 ), Y is C or NH, and R 6 is CH3. These novel amphipathic diblock copolymers may be formulated for use: as a lens care component for silicone hydrogel contact lenses; as an oxygen permeable and wettable backing material for a wound healing device; as a scaffold for tissue engineering; or as a component for controlled drug release. [0009] This invention also provides a (meth)acrylated polyvinylpyrrolidone compound of the gcncral structure depicted blow. iH f 2 -0'O n R4 wherein R, is hydrogen or C,.g-alkyl, preferably H; R 2 is pyrrolidinone; n = 1 - 10,000; R is a divalent aliphatic linkage chain containing up to 8 carbon atoms and up to 2 oxygen, sulfur, and/or nitrogen atoms in the linkage chain, such as C(CH 3

)

2

-CH

2

-CH

2 , C(CH 3

)

2 , S-(CH 2

)

2 ,

C(CH

3

)

2 -0-C(=O)-NH-(CH 2

)

2 , C(CH1 3

)

2 -C1 2

-CH

2 -0-C(=O)-NH-(CH,) 2 , or S-(CH 2 )rO

C(=O)-NH-(CH

2 )2; and R 4 is hydrogen or C 1 .s-alkyl, such as CH 3 . In specific embodiments: Ri = H, R 3 = C(CH 3

)

2

-O-CH

2

-CH

2 , R 4 = CT3, and n = 10 - 1000; or R, = H, R 3 = C(CH3)2, R4= H, and n = 10 - 1000, or R, = H, R 3 = S-(CH 2

)

3 , R4= CH 3 , and n = 10 - 1000, orRi = H, R 3 = C(CH 3 )rO-C(=O)-NH-(CH 2

)

3 , R 4 = CH 3 , and n = 10 - 1000. This compound is suitable for usc as a polymcrizable wetting agent in a contact lens formulation. [00101 This invention likewise provides a (meth)acrylamide functionalized polyvinylpyrrolidone of the general structure depicted below, which is likewise suitable for use as a polymerizable wetting agent in a contact lens formulation. R1 0 1 H R3' N

R

2 H R4 In the formula: Ri is hydrogen or CI.s-alkyl; R 2 is pyrrolidinone; n = I - 10,000; R 3 is a divalent aliphatic linkage chain containing up to 8 carbon atoms and up to 2 oxygen, sulfur, and/or nitrogen atoms in the linkage chain, such as S-(CH 2 )m 1 wherein m is 1-6; and R 4 is hydrogen or Ci..-alkyl, such as CH 3 . In specific embodiments, R, =H, R 3 = S-(CH 2 )m,, "in"= 5 I to 6, R 4 - H, and n = 10 - 10,000 or R, = H, R 3 = S-(CHl 2 )m, "m"= 1 to 3,R 4 = Cl43, and n = 10 - 10,000. DETAILED DESCRIPTION OF TIE INVENTION [0011] The present invention provides methods for preparation of PVP with polymerizable functionalization ror use, e.g., as hydrophilic wetting agents in contact lenses. The present invention provides a new class of compositions of matter, comprising functionalized hybrid PDMS/polar amphipathic copolymer block systems. Those materials may be used in both industrial and biomedical devices such as components for ophthalmic devices (hydrogels), tissue engineering, transdermal implants, industrial adhesives, sealants, surface protecting agents, etc. For instance, (meth)acrylated PVP derivatives will find effective use in contact lens compositions that contain photopolymerizable components. In practice, during irradiation of the contact lens mix, the (meth)acrylated PVP will polymerize along with the other polymerizable components to provide a non-lcachable lens. [00121 As illustrated in detail herein below, their synthesis may involve preparing a PDMS free radical macroinitiator followed by polymerization in the presence of N-vinyl pyrrolidone or other polar vinyl or acrylic monomers susceptible to free radical polymerization in the presence of a CTA (chain transfer agent) such as IPA, isopropoxyethanol or mercaptoethanol to generate the OH- functionalized polymer. The resulting polymer may be methacrylated using different chemistries by reacting the 01- group with methacryloyl chloride or Methacrylic anhydride in the presence of a base or alternatively by reaction with isocyanatoethyl methacrylate. [00131 Using this approach a variety of methacrylate (MA) functionalized PDMS-polar copolymer blocks can be synthesized. Examples of materials of interest are PDMS-PVP MAA and PDMS-polyNTPAAm-MA. The chemistry may also be extended to prepare difunctional methacrylate functionalized triblock copolymers such as MA-PVP-PDMS-PVP MA and other polymer, starting with commercially available dihydroxy- or diamino functionalized polydimethylsiloxanes. Persons skilled in the art are familiar in general with the production of block copolymers having functionally active endgroups. For instance, US 6 5,589,563 (Polymer Tecimology Group), the disclosure of which is herein incorporated by reference, discloses how to make and use functionalized copolymers. EXAMPLES Example 1: (Metb)acrylated PVP polymers [0014 The synthesis of meth(acrylate) functionalized PVP is achicycd by a methacrylation reaction of hydroxy functionalized PVP that is prepared using reactions known to those skilled in the art. The general structure of polymerizable (mcth)acrylated PVP may have, for instance, the following formula: R1 0 H R 3

O

0 )Q n R4 R1 = H; R 2 = pyrrolidinone,

R

3 = C(CH 3

)

2

-O-CH

2

-CH

2 , C(CH 3

)

2 , or S-(CH 2

)

3 , C(CH 3

)

2 -0-C(=0)-NH-(CH 2

)

3 ;

R

4 = H or CH3; n= 1-1000 The first step toward the synthesis of (meth)acrylated PVP copolymers is the polymerization of distilled N-vinyl-2-pyrrolidone using azo initiators such as azobis(isobutyronitrile) (AIBN) and the like in the presence of chain transfer agents such as isopropanol, mercaptocthanol, isopropoxyethanol with or without a solvent to generate hydroxyl terminated PVP of different MW's between 10,000 to 1,000,000 daltons. The resulting hydroxyl terminated PVP is converted to a terminal methacrylate derivative using either methacryloyl chloride, methacrylic anhydride, or isocyanatoethyl methacrylate. One example of this embodiment is synthesized using protocol shown in Scheme 1. CI O1 HS l -H , H AIBN O Tnethyiamine n Scheme 1: Synthesis of methacrylated PVP polymer. Example 2: (Meth)acrylamide functionalized PVP polymers 7 100151 Another class of polymerizable PVP is depicted below, wherein the polymerizable functionalization is a (meth)acrylamide group. 0 H R3 2 n-n R 4 R1= H; R 2 = pyrrolidinone,

R

3 = S-(CH2)m, m = 1- 6

R

4 = H or CH 3 ; n= 1-1000 The first step toward the synthesis of (meth)acrylamidc functionalized PVP copolymers is the polymerization of distilled N-vinylpyrrolidone using azo initiators such as azobis(isobutyronitrile) (AIBN) and the like in the presence of an aminoalkylnercaptan chain transfer agent with or without a solvent to generate amino terminated PVP of different MW's between 10,000 to 1,000,000 daltons. The resulting amino terminated PVP is converted to a terminal (mcth)acrylamidc derivative by reaction with methacryloyl chloride, or methacrylic anhydride. One example of this embodiment is synthesized using protocol illustrated in Scheme 2. HSM NH2 HC H H -~ H AIBN Hn Triethylamine - n CXOI ~CH 2

CI

2 X Scheme 2: Synthesis of an acrylamide terminated PVP polymer. Example 3: Amphipathic diblock copolymers Including PDMS-PVP copolymers [0016] The present invention also provides methods for preparation of novel polydimethylsiloxane (PDMS) - PVP copolymers and other amphipathic copolymers of the general structure depicted in the following formula. YH3 CH3 H3 R aC 3 bO CC R 4 - d R= alkyl, alkoxy; R 2 = (CH2)n; (CH2)m-O(CH2)n, m and n can be between 1-16 a = 1-200; b = 1-6; c = 1-6; d = 1-1000; X = 0, NH, S; R 3 = H, CH3; R 4 = pyrrolidinone, C(=O)OH, C(=0)OAIkyI, Ph, substituted Ph, C(=0)NH2, C(=O)N(alkyl)2, OC(=0)CH3, OH, C(=0)-oxylethylphosphorycholine A retmsynthetic process for the preparation of the above class of matter is depicted in the following reaction scheme: 8 R3 RRX3 aC 3 b O -c CN . R4 - d R, = alkyi. alkoxy; R 2 = (CH2)n; (CH2)m-O(CH2)n, m and n can be between 1-16 a - 1-200; b = 1-6; c = 1-6; d = 1-1000; X = 0, NH, S; R 3 = H, CH3; R 4 = =pyrrofidinone, C(=O)OH, C(=O)OAlkyl, Ph, substituted Ph, C(=O)NH2, C(=O)N(alkyl)2, OC(=O)CH3, OH, C(=O)-oxylethylphosphorycholine RS = C(CH3)2-O-CH2-CH2, C(CH3)2, or S-(CH2)3, O-C(=O)-NH-(CH2)2 R1 R 21N=N- + = ~g &-i R~j{ R4 II R R XH + HO N=N Commercially available or [c -2, commercially available specifically made Azobis(4-cyanovaleric acid)] Example 4: Amphipathic triblock copolymers including PVP-PDMS-PVP copolymers [0017] The synthetic methodology provided by the present invention also allows synthesis of novel PVP-PDMS-PVP triblock copolymers and other amphipathic copolymers of the general structure depicted in the following formula: H XH 3 C R 1 HR3 CHi I + CH 3

R

3 -H

.R

4 d CN CO b a bO -c CN R d

R

2 = (CH2)n; (CH2)m-O(CH2)n, m and n can be between 1-16 a = 1-200; b = 1-6; c = 1-6; d = 1-1000; X = 0, NH, S; R 3 = H, CH3; R 4 pyrrolidinone, C(=O)OH, C(=O)OAkyI, Ph, substituted Ph, C(=O)NH2, C(=O)N(alkyl)2, OC(=O)CH3, OH, C(=0)-oxylethylphosphorycholine A retrosynthetic approach for the preparation of the above class of matter is depicted in the following reaction scheme, which like that in Example 3 shows the final product preceded by the intermediates which provide it preceded by the starting materials.

9 HR Si X33 H, C J R RH HH 3 H - 0i I tC .R4 Cd -CO b a b 0.- cCN R 4 -d R2 = (CH2)n; (CH2)m-O(CH2)n, m and n can be between 1.16 a= 1-200; b = 1-6; c = 1-6; d = 1-1000; X = 0, NH, S; R 3 = H, CH3; R 4 = pyrrolidinone, C(=O)OH, C(=O)OAlkyl, Ph, substituted Ph, C(=O)NH2, C(=O)N(alkyl)2, OC(=O)CH3, OH, C(=O)-oxylethylphosphorycholine CH3 CH3 OH OH 1 R 3 .i CHI R Ri i -X N= + ON cO cCN in

CH

3

OH

3 OH 3 HX Si SI R HXH H O N=N bC H cCN 2 Commercially available or [c =2, commercially available specifically made Azobis(4-cyanovalerc acid)] Example 5: Monofunctional polymerizable amphipathic copolymers including PDMS PVP methacrylate copolymers [00181 Another embodiment of the invention is general class of compounds bearing polymerizable functionality as depicted in the following formula: [CH31 CH 3 0 3 R3 Rf R -X3 R1 s - -a b 0 - CN - R4- Rs R1 = alkyl, alkoxy; R 2 = (CH2)n; (CH2)m-O(CH2)n, m and n can be between 1-16 a = 1-200; b = 1-6; c = 1-6; d = 1-1000; X = 0, NH, S; Y = 0, NH

R

3 = H, CH3; R 4 = pyrrolidinone, C(=O)OH, C(=0)OAlkyl, Ph, substituted Ph, C(=O)NH2, C(=0)N(alkyl)2, OC(=O)CH3, OH, C(=O)-oxylethylphosphorycholine

R

5 = C(CH3)2-0-CH2-CH2, C(CH3)2, or S-(CH2)3, O-C(=O)-NH-(CH2)2; RS = H or CH3 A retrosynthetic approach for the preparation of the above class of matter is depicted in Scheme 5.

10 r4 ?H 91.3 1

H

3

R

3 a 3 JC3 b 0 C d R 6 R1 - alkyl. alkoxy; R 2 = (CH2)n; (CH2)m-O(CH2)n, m and n can be between 1-16 a = 1-200; b = 1-0; c = 1-6; d - 1-1000; X = 0, NH. S; R 3 =H, CH3; R 4 = =pyrrolldinone, C(=O)OH. C(=O)OAlkyl, Ph, substituted Ph, C(=O)NH2, C(=0)N(alkyl)2. OC(0O)CH3, OH, C(=O)-oxylethylphosphorycholine R5 a C(CH3)2-0-CH2-CH2, C(CH3)2, or S-(CH2)3, O-C(=O)-NH-(CH2)2; Re = H or CH3 Rb 0+HR R'O {R 4 H 4R X N=N + H-RSHRH

_[H

3 3CN F]Rrrl1-1l R1J ~ ~ j bXH +4 jC - $ 1 - ' N-N- Commercially available or specifically made -i CH N=N- [c -2, commercially available 1-1 AzobLs(4-cyanovaleric acid)] [00191 As disclosed above, compositions of matter provided by the present invention may be used - among other things -- to make silicone hydrogel contact lenses. Persons skilled in the art are well aware in general of methods of manufacturing such contact lenses. Reference is made, for instance, to US 7,268,198 B2 (Bausch & Lomb), entitled SILICONE HYDROGEL CONTACT LENSES; to US 6,861,123 B2, (Johnson & Johnson), entitled SILICONE 1HYDROGEL CONTACT LENS; and to US 5,260,000 (Bausch & Lomb), entitled PROCESS FOR MAKING SILICONE CONTAINING HYDROGEL LENSES. 100201 The invention being thus described generically and with reference to specific embodiments, it will be readily apparent to thosc skilled in the art that the same may be 11 varied in many ways. All such variations are encompassed by the spirit of the invention, the patented scope of which is demarcated in the appended claims.

Claims (6)

1. A (meth)acrylamide functionalized polyvinylpyrrolidone of the general structure depicted below, suitable for use as a polymerizable wetting agent in a contact lens formulation: R1O .d K Ra - N 'R

2 J H 5 wherein R 1 is hydrogen or CI- 8 -alkyl; R 2 is pyrrolidinone; n = 1 -10,000; R 3 is a divalent aliphatic linkage chain containing up to 8 carbon atoms and up to 2 oxygen, sulfur, and/or nitrogen atoms in the linkage chain; and R 4 is hydrogen or Ci-s-alkyl. 10 2. The compound of claim 1, wherein in R 3 is S-(CH 2 )m wherein m is 1-6.

3. The compound of claim 1, wherein in R 4 is CH 3 .

4. The compound of claim 1, wherein R, = H; R 3 = S-(CH 2 )m; "M" = I to 6; R 4 = H; and n= 10 15 10,000.

5. The compound of claim 1, wherein R = H; R 3 = S-(CH 2 )m; "M" = I to 3; R 4 = CH 3 ; and n = 10 - 10,000. 0

6. The compound of claim 1, substantially as hereinbefore described with reference to any one of the Examples.