Biodegradable absorbents and methods of preparation

• US 20030069369A1
• Filed: 10/09/2002
• Published: 04/10/2003
• Est. Priority Date: 10/10/2001
• Status: Active Grant

• Current Assignee: Maksim Belenkiy
• Original Assignee: Bronislava G. Belenkaya, Valentina I. Sakharova, Vyacheslav N. Polevov
• Inventors: Polevov, Vyacheslav N., Belenkaya, Bronislava G., Sakharova, Valentina I.
• Granted Patent: US 7,309,498 B2
• Time in Patent Office: Days
• US Class Current: 525/437
• CPC Class Codes: A61F 13/00063 comprising medicaments or additives, e.g. odor control, PH control, debriding, antimicrobic drug delivery dressings A61K9/70; chemical aspect of the additives A61L15/00
• CPC Class Codes: A61F 13/00995 for mechanical treatments
• CPC Class Codes: A61F 13/01042 Absorbency
• CPC Class Codes: A61F 2013/00097 net structure
• CPC Class Codes: A61F 2013/00157 for burns or skin transplants A61F2013/00187 takes precedence; not adhering to the wound A61F2013/00217
• CPC Class Codes: A61F 2013/00246 in a special way pervious to air or vapours
• CPC Class Codes: A61F 2013/00357 implanted wound fillings or covers membranes for covering bone defects A61F2/2846
• CPC Class Codes: A61F 2013/00472 with chemical means
• CPC Class Codes: A61F 2013/00519 for treating burn bandages for burns or skin transplants A61F2013/00157
• CPC Class Codes: A61F 2013/00544 form or structure
• CPC Class Codes: A61F 2013/00646 Medication patches, e.g. transcutaneous
• CPC Class Codes: A61F 2013/00744 containing non-woven
• CPC Class Codes: A61F 2013/0091 with disinfecting or anaesthetics means, e.g. anti-mycrobic
• CPC Class Codes: A61F 2013/00927 with biological activity, e.g. enzymes for debriding wounds or others, collagen or growth factors
• CPC Class Codes: A61F 2013/15447 Fibre dimension, e.g. denier or tex
• CPC Class Codes: A61L 15/225 Mixtures of macromolecular compounds
• CPC Class Codes: A61P 29/00 Non-central analgesic, antipyretic or antiinflammatory agents, e.g. antirheumatic agents; Non-steroidal antiinflammatory drugs [NSAID]
• CPC Class Codes: A61P 31/00 Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
• CPC Class Codes: A61P 31/04 Antibacterial agents
• CPC Class Codes: A61P 31/10 Antimycotics
• CPC Class Codes: A61P 7/00 : Drugs for disorders of the blood or the extracellular fluid
• CPC Class Codes: C08L 2666/02 : Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/04 : Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 39/04 : Homopolymers or copolymers of monomers containing heterocyclic rings having nitrogen as ring member
• CPC Class Codes: C08L 39/06 : Homopolymers or copolymers of N-vinyl-pyrrolidones
• CPC Class Codes: C08L 67/02 : Polyesters derived from dicarboxylic acids and dihydroxy compounds C08L67/06 takes precedence
• CPC Class Codes: C08L 67/025 : containing polyether sequences
• CPC Class Codes: C08L 67/04 : Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: D01D 5/0038 : the fibre formed by solvent evaporation, i.e. dry electro-spinning
• CPC Class Codes: D01D 5/0069 : characterised by the spinning section, e.g. capillary tube, protrusion or pin
• CPC Class Codes: D01F 1/10 : Other agents for modifying properties
• CPC Class Codes: D01F 6/56 : of polymers of cyclic compounds with one carbon-to-carbon double bond in the side chain
• CPC Class Codes: D01F 6/92 : of polyesters
• CPC Class Codes: D06M 23/08 : Processes in which the treating agent is applied in powder or granular form adhesives for multi-layer textile fabrics D06M17/00

Abstract

A biodegradable microfiber absorbent comprises a substantially homogeneous mixture of at least one hydrophilic polymer and at least one biodegradable polymer. The absorbent can be prepared by an electro hydrodynamic spinning of a substantially homogeneous polymer mixture. Medical dressings for burns and wounds, cavity dressings, drug delivery patches, face masks, implants, drug carriers that comprises at least one microfiber electrospun from a polymer mixture are provided. The dressings can have variable water vapor penetration characteristics and variable biodegradation times.

Claims

1. A method for preparing a biodegradable microfiber absorbent, the method comprising electrohydrodynamic processing of a mixture containing:

(a) at least one hydrophilic polymer which is a poly (N-vinyl) lactam; and

(b) at least one biodegradable polyester;

wherein the lactam is not poly-(N-vinyl) pyrrolidone and/or the polyester is not polylactide.

9. The method of any one of claims 1-5, 7 further comprising incorporating into the absorbent at least one therapeutic performance enhancing additive comprising one or more of living cells, proteins, peptides, antibiotic compounds, bacteriocidal compounds, fungicidal compounds, bacteriostatic compounds, analgesic compounds, trombogenic compounds that promote wound healing, wherein the absorbent is deposited on a backing film and the baking film containing the same or different medications.

12. The method of any one of claims 1, 2, 3, 7, 11 wherein the electrohydrodynamic processing comprises emitting a flow of said mixture into an area in which said mixture flies in an electrical field towards a substrate;

and the method further comprises emitting a flow of dry particles into said area and the dry particles being deposited over said substrate.

13. The method of claim 12 wherein the flow of dry particles and the flow of said mixture are emitted into said area in overlapping periods of time.

19. A product made by the method of claim 1.

2. A method for preparing a biodegradable microfiber absorbent, the method comprising electrohydrodynamic processing of a mixture containing:

(a) a solvent;

(b) poly-(N-vinyl) pyrrolidone; and

(c) a biodegradable polyester which is polylactide of a molecular mass at least 125000 Dalton, with a component ratio of the poly-(N-vinyl) pyrrolidone to the polylactide by weight being from about 2;

98 to about 9;

91 or from about 31;

69 to about 50;

50.

6. The method of any one of claims 2-5 wherein said mixture further comprises one or more low molecular weight biodegradable polyesters with hydroxyl, carboxyl or amino-terminal groups, and/or one or more polyoxyethylene glycols, and/or one or more low molecular weight alcohols selected from the group containing alcohols, including alcohols of natural origin.

16. A medical dressing comprising a biodegradable microfiber absorbent prepared by the method of claim 2, 3, 4 or 5.

20. A product made by the method of claim 2.

3. A method for preparing a biodegradable microfiber absorbent, the method comprising electrohydrodynamic processing of a mixture containing:

(a) a solvent;

(b) poly-(N-vinyl) pyrrolidone; and

(c) a biodegradable polyester which is a copolymer of lactide with glycolide or a blend of a copolymer of lactide with glycolide with a homopolymer of lactide, with a component ratio of the poly-(N-vinyl) pyrrolidone to the biodegradable polyester by weight being from about 2;

98 to about 50;

50.

21. A product made by the method of claim 3.

4. A method for preparing a biodegradable microfiber absorbent, the method comprising electrohydrodynamic processing of a mixture containing:

(a) at least one hydrophilic polymer which is a poly (N-vinyl) lactam; and

(b) at least one biodegradable polyester;

wherein said hydrophilic polymer is poly-(N-vinyl) pyrrolidone and said biodegradable polyester is a homopolymer of caprolactone or a copolymer of caprolactone and lactide or a blend thereof, wherein a component ratio by weight of the poly-(N-vinyl) pyrrolidone to the biodegradable polyester is from about 10;

90 to about 50;

50.

22. A product made by the method of claim 4.

5. A method for preparing a biodegradable microfiber absorbent, the method comprising electrohydrodynamic processing of a mixture containing:

(a) at least one hydrophilic polymer which is a poly (N-vinyl) lactam; and

(b) at least one biodegradable polyester;

wherein said hydrophilic polymer is poly-(N-vinyl) pyrrolidone and said biodegradable polyester is a homopolymer of p-dioxanon, or a copolymer of p-dioxanon and glycolide, or a copolymer of p-dioxanon and lactide or a blend thereof, wherein a component ratio by weight of the poly-(N-vinyl) pyrrolidone to the biodegradable polyester is from about 10;

90 to about 50;

50.

23. A product made by the method of claim 5.

7. A method for preparing a biodegradable microfiber absorbent, the method comprising electrohydrodynamic processing of a mixture containing:

(a) a solvent;

(b) at least one hydrophilic polymer which is a polyvinyl lactam; and

(c) at least one biodegradable polyester;

wherein the microfiber absorbent is deposited on a biodegradable hydrophobic thin film at most 15 μ

m in thickness, where the film is prepared from homopolymers of lactide, or glycolide, or caprolactone, or p-dioxanon, or copolymers and/or the blends thereof.

8. The method of claim 7 wherein the hydrophobic film comprises a blend of a biodegradable polymer and a low molecular weight biodegradable polyester with hydroxyl, carboxyl and/or amino-terminal groups, and/or polyoxyethylene glycols, and/or low molecular alcohols selected from the group containing of multifunctional alcohols, including alcohols of natural origin.

18. A medical dressing comprising a biodegradable microfiber absorbent prepared by the method of claim 7 wherein the hydrophobic film is a protective backing layer and the biodegradable microfiber absorbent is a facing layer.

24. A product made by the method of claim 7.

10. A method for preparing a biodegradable microfiber absorbent, the method comprising forming a plurality of layers comprising a first biodegradable microfiber absorbent layer and a second biodegradable microfiber absorbent layer over the first biodegradable microfiber absorbent layer, wherein each of the first and second layers is formed by electrohydrodynamic processing of a mixture containing:

(a) a solvent;

(b) at least one hydrophilic polymer which is a polyvinyl lactam; and

(c) one or more biodegradable polyesters;

(d) one or more medications;

wherein the one or more medications of the first layer are different from the one or more medications of the second layer, and/or the one or more biodegradable polymers of the first layer have a different composition than the one or more biodegradable polymers of the second layer.

25. A product made by the method of claim 10.

11. A method for preparing a biodegradable microfiber absorbent, the method comprising electrohydrodynamic spinning of a substantially homogeneous mixture comprising at least one hydrophilic polymer and at least one biodegradable polymer, the electrohydrodynamic spinning being performed at a voltage from about 20 to about 30 kV or from about 65 to about 90 kV.

14. The method of claim 11 wherein the mixture further comprises at least one therapeutic performance-enhancing additive.

15. The method of claim 11 wherein the mixture has an intrinsic viscosity from about 0.1 to about 10 poise.

17. The medical dressing of claim 14 wherein the absorbent is capable to absorb at 20 g/g of water or blood or both.

26. A product made by the method of claim 11.

27. A biodegradable microfiber absorbent comprising:

(a) at least one hydrophilic polymer which is a polyvinyl lactam; and

(b) at least one biodegradable polymer that is a biodegradable polyester;

wherein the lactam is not PVP and/or the polyester is not polylactide; and

wherein the biodegradable microfiber absorbent is haemostatic, antiseptic, and has a wound healing ability.

30. The absorbent of claim 27 wherein said hydrophilic polymer is poly-(N-vinyl) pyrrolidone and said biodegradable polyester is a homopolymer of caprolactone or a copolymer of caprolactone and lactide or a blend, wherein a component ratio by weight of the poly-(N-vinyl) pyrrolidone to the biodegradable polyester is from about 10:

90 to about 50;

50.

31. The absorbent of claim 27 wherein said hydrophilic polymer is poly-(N-vinyl) pyrrolidone and said biodegradable polyester is a homopolymer of p-dioxanon, or a copolymer of p-dioxanon and glycolide, or a copolymer of p-dioxanon and lactide, or a blend thereof, wherein a component ratio by weight from about 10:

90 to about 50;

50.

35. The biodegradable microfiber absorbent of any one of claims 27-29, 33 further comprising at least one therapeutic performance enhancing additive selected from the group consisting of living cells like keratinocytes or fibroblasts, or antibiotic compounds, bacteriocidal compounds, fungicidal compounds, bacteriostatic compounds, analgesic compounds, trombogenic compounds that promote wound healing, and proteins containing drugs, wherein the absorbent is formed on a backing film, the backing film and the absorbent containing the same or different medications.

28. A biodegradable microfiber absorbent comprising:

(a) poly-(N-vinyl) pyrrolidone; and

(b) a biodegradable polyester which is polylactide of molecular mass at least 1250000 Dalton, with a component ratio of the poly-(N-vinyl) pyrrolidone to the polylactide by weight being from about 2;

98 to about 9;

91 or from about 31;

69 to about 50;

50;

wherein the biodegradable microfiber absorbent is haemostatic, antiseptic and has a wound healing ability.

32. The absorbent of any one of claims 28, 29 further comprising one or more low molecular weight biodegradable polyesters with hydroxyl, carboxyl or amino-terminal groups, and/or one or more polyoxyethylene glycols, and/or one or more low molecular weight alcohols selected from the group containing alcohols, including alcohols of natural origin.

29. A biodegradable microfiber absorbent comprising:

(a) poly-(N-vinyl) pyrrolidone; and

(c) a biodegradable polyester which is a copolymer of lactide with glycolide or a blend of a copolymer of lactide with glycolide with a homopolymer of lactide, with a component ratio of the poly (N-vinyl) pyrrolidone to the biodegradable polyester by weight being from about 2;

98 to about 50;

50, wherein the biodegradable microfiber absorbent is haemostatic, antiseptic and has a wound healing ability.

33. A biodegradable microfiber absorbent comprising:

(a) at least one hydrophilic polymer which is a polyvinyl lactam; and

(b) at least one biodegradable polyester;

wherein the microfiber absorbent is deposited on a biodegradable hydrophobic thin film at most 15 μ

m in thickness, where the film is prepared from homopolymers of lactide, or glycolide, or caprolactone, or p-dioxanon, or copolymers and/or the blends thereof; and

wherein the biodegradable microfiber absorbent is haemostatic, antiseptic and has a wound healing ability.

34. The biodegradable microfiber absorbent of claim 33 wherein the hydrophobic film comprises a blend of a biodegradable polymer and a low molecular weight biodegradable polyester with hydroxyl, carboxyl and/or amino-terminal groups, and/or polyoxyethylene glycols, and/or low molecular alcohols selected from the group containing of multifunctional alcohols, including alcohols of natural origin.

36. A biodegradable microfiber absorbent, comprising a plurality of layers comprising a first biodegradable microfiber absorbent layer and a second biodegradable microfiber absorbent layer over the first biodegradable microfiber absorbent layer, wherein each of the first and second layers comprises:

(a) at least one hydrophilic polymer which is a polyvinyl lactam; and

(b) one or more biodegradable polyesters;

(c) one or more medications;

wherein the one or more medications of the first layer are different from the one or more medications of the second layer, and/or the one or more biodegradable polymers of the first layer have a different composition than the one or more biodegradable polymers of the second layer.