Process for the manufacture of an ophthalmic molding

• US 6,039,913 A
• Filed: 08/27/1998
• Issued: 03/21/2000
• Est. Priority Date: 08/27/1998
• Status: Expired due to Term

• Current Assignee: Novartis Ag
• Original Assignee: Novartis Ag
• Inventors: Hirt, Thomas, Meier, Wolfgang Peter, Lohmann, Dieter, Baron, Richard Carlton
• Primary Examiner(s): Marquis, Melvyn I.
• Application Number:
  US09/141,252
• Time in Patent Office: 572 Days
• Field of Search: 524/805, 525/100, 528/25, 528/14, 528/26, 528/28, 523/106, 523/107, 264/331.15, 264/331.16, 264/331.18, 264/331.11, 264/331.19, 264/330
• US Class Current: 264/331.11
• CPC Class Codes: A61F 2/142 Cornea, e.g. artificial corneae, keratoprostheses or corneal implants for repair of defective corneal tissue
• CPC Class Codes: A61F 2/16 Intraocular lenses
• CPC Class Codes: A61L 27/14 Macromolecular materials
• CPC Class Codes: A61L 27/16 obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/18 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: B01D 2323/24 Use of template or surface directing agents [SDA]
• CPC Class Codes: B01D 2323/30 Cross-linking
• CPC Class Codes: B01D 2323/34 Use of radiation
• CPC Class Codes: B01D 67/0006 by chemical reactions in-situ polymerisation, polycondensation, cross-linking or reaction for manufacturing composite membranes B01D69/125
• CPC Class Codes: B01D 71/40 Polymers of unsaturated acids or derivatives thereof, e.g. salts, amides, imides, nitriles, anhydrides, esters
• CPC Class Codes: B01D 71/401 Polymers based on the polymerisation of acrylic acid, e.g. polyacrylate
• CPC Class Codes: B01D 71/402 Polymers based on the polymerisation of fumaric acid or derivatives thereof
• CPC Class Codes: B01D 71/403 Polymers based on the polymerisation of maleic acid or derivatives thereof
• CPC Class Codes: B01D 71/52 Polyethers
• CPC Class Codes: B01D 71/5211 Polyethylene glycol or polyethyleneoxide
• CPC Class Codes: B01D 71/70 Polymers having silicon in the main chain, with or without sulfur, nitrogen, oxygen or carbon only
• CPC Class Codes: B01D 71/701 Polydimethylsiloxane
• CPC Class Codes: B01D 71/76 Macromolecular material not specifically provided for in a single one of groups B01D71/08 - B01D71/74 rubbers in general B01D71/24
• CPC Class Codes: C08J 5/00 Manufacture of articles or shaped materials containing macromolecular substances manufacture of semi-permeable membranes B01D67/00 - B01D71/00
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene
• CPC Class Codes: C08L 53/00 : Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 83/10 : Block- or graft-copolymers containing polysiloxane sequences obtained by polymerising a compound having a carbon-to-carbon double bond on to a polysiloxane C08L51/08, C08L53/00
• CPC Class Codes: G02B 1/043 : Contact lenses

Abstract

The present invention relates to a process for the manufacture of a molding, which comprises the following steps:

a) providing at least one prepolymer comprising one or more crosslinkable groups, wherein the prepolymer is an amphiphilic segmented copolymer comprising at least one hydrophobic segment A and one hydrophilic segment B;

b) preparing a mesophase of the prepolymer which is at least partly bicontinuous;

c) introducing the mesophase obtained into an ophthalmic mold;

d) triggering of the crosslinking; and

e) opening the mold such that the molding can be removed. The process of the invention is particularly suited for the manufacture of membranes and ophthalmic moldings such as contact lenses.

Claims

1. A process for the manufacture of a molding, which comprises the following steps:

a) providing at least one prepolymer comprising one or more crosslinkable groups, wherein the prepolymer is an amphiphilic segmented copolymer comprising at least one hydrophobic segment and one hydrophilic segment;

b) preparing an at least partly bicontinuous mesophase of the prepolymer by combining the prepolymer with an aqueous solution at a ratio that will give a microstructure which is at least partly bicontinuous and causing or allowing the bicontinuous microstructure to form;

c) introducing the mesophase obtained into an ophthalmic mold;

d) crosslinking the prepolymer to form the molding; and

e) opening the mold such that the molding can be removed.

2. A process according to claim 1, wherein the molding is selected from the group consisting of ophthalmic moldings, membranes, catalysts and moldings that are useful in surgery.

3. A process according to claim 1, wherein the prepolymer has a weight average molecular weight of from 1000 to 50000.

4. A process according to claim 1, wherein the hydrophobic segment of the prepolymer is a polysiloxane or perfluoropolyalkyl ether.

5. A process according to claim 1, wherein the hydrophilic segment of the prepolymer is a non-ionic segment selected from the group consisting of a polyoxyalkylene, polysaccharid, polypeptide, poly(vinylpyrrolidone), polyalkylacrylate and -methacrylate, polyhydroxyalkylacrylate and -methacrylate, polyacyl alkylene imine, polyacryl amide, polyvinyl alcohol, polyvinyl ether and polyol, or is a polycationic segment selected from the group consisting of a polyallylammonium, polyethyleneimine, polyvinylbenzyltrimethylammonium, polyaniline, sulfonated polyaniline, polypyrrole and polypyridinium segment, or is a polyanionic segment selected from the group consisting of a polyacrylic and polymethacrylic acid, a polythiophene-acetic acid, a polystyrenesulfonic acid and a suitable salt thereof.

6. A process according to claim 1, wherein the hydrophobic and hydrophilic segments of the prepolymer are linked by a non-hydrolizable bond or by a bridge member selected from the group consisting of a carbonyl, carbonate, ester, amide, urea or urethane functional group and an alkylene, cycloalkylene, aralkylene, arylene or heterocyclic group containing one or two of the functional groups mentioned.

7. A process according to claim 1, wherein the prepolymer contains the hydrophobic and hydrophilic segments linked together through a non-hydrolizable bond, and the hydrophobic segment comprises a polysiloxane block having terminal alkylene groups of the formula ##STR12## in which n is an integer from 5 to 700;

Alk is alkylene having up to 20 carbon atoms;

80-100% of the radicals R₁, R₂, R₃ and R₄, independently of one another, are alkyl and 0-20% of the radicals R₁, R₂, R₃ and R₄, independently of one another, are alkenyl, aryl, fluoroalkyl or cyanoalkyl.

8. A process according to claim 7, wherein the hydrophilic segment of the prepolymer is a polyacyl alkylene imine segment which is derivable from a cyclic imino ether of Formula (IV) ##STR13## wherein R₉ represents a hydrogen atom, an alkyl, hydroxyalkyl or alkenyl group having up to 22 carbon atoms and optionally containing an ether, ester or urethane group, a cycloalkyl group, an aralkyl group or an aryl group;

and t is 2 or 3.

9. A process according to claim 8, wherein the cyclic imino ether is 2-methyl-2-oxazoline, a 2-alkenyl oxazoline, a 2-(hydroxyalkyl)oxazoline or a 2-isocyanatoethylmethacrylate thereof.

10. A process according to claim 1, wherein the prepolymer is of the formula

11. A process according to claim 1, wherein the prepolymer comprises at least one segment of the formula (VI):

##STR14## in which (a) is a polysiloxane segment,

(b) is a polyol segment which contains at least 4 C atoms,

Z₁ is a segment X₂ --R'"'"'--X₂ or a group X₁,

R'"'"' is a bivalent radical of an organic compound having up to 20 C atoms and

X₁ and each X₂ independently of the other are a bivalent radical which contains at least one carbonyl group, and

(d) is a radical of the formula (VII);

##STR15## in which P₁ is a group which can be polymerized by free radicals;

Y and X₃ independently of one another are a bivalent radical which contains at least one carbonyl group;

k1 is 0 or 1; and

L is a bond or a divalent radical having up to 20 C atoms of an organic compound.

12. A process according to claim 1, wherein the mesophase is prepared by combining two or more prepolymers, with an aqueous solution.

13. A process according to claim 12, wherein the aqueous solution comprises pure water or a mixture of water and one or more water-miscible solvents and/or salts.

14. A process according to claim 1, wherein the mesophase is prepared by combining the prepolymer with an aqueous solution and one or more components selected from the group consisting of a photoinitiator, a thermal initiator, a redox initiator, a surfactant, a comonomer, a comacromer and a pharmaceutical effective agent.

15. A process according to claim 1, wherein the mesophase is prepared from the prepolymer;

water which may contain physiologically acceptable salts; and

optionally a photoinitiator and/or an additional solvent selected from the group consisting of a monohydric or polyhydric alcohol, a polyether, a carboxylic acid amide, acetone, acetonitrile and dimethyl sulfoxide.

16. A process according to claim 1, wherein the mesophase is prepared from the prepolymer, water and optionally a photoinitiator.

17. A process according to claim 1, wherein the bicontinuous microstructure is caused to form by admixing the prepolymer, the aqueous solution and optionally further components selected from the group consisting of a photoinitiator, a thermal initiator, a redox initiator, a surfactant, a comonomer, a comacromer, and a pharmaceutical effective agent;

and keeping the mixture at a temperature of 0 to 100°

C. for a time period from 1 minute to 1 week with optional stirring.

18. A process according to claim 1, wherein the formation of the mesophase comprises preparing a melt of the prepolymer and optionally further components selected from the group consisting of a photoinitiator, a thermal initiator, a redox initiator, a surfactant, a comonomer, a comacromer, and a pharmaceutical effective agent.

19. A process according to claim 1, wherein the mesophase obtained according to step b) is of a crystalline structure.

20. A process according to claim 1, wherein the crosslinking is carried out for a time period of ≦

60 minutes.

21. A process according to claim 1, wherein the molding is a contact lens.

22. A contact lens, obtainable according to the process of claim 1.

23. A process according to claim 1, wherein the molding is a membrane.

24. A membrane, obtainable according to the process of claim 1.