US5099013A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hylan preparation and method of recovery thereof from animal tissues
Assignee: Biomatrix Inc
•
Filing: 1990-11-16
•
Granted: 1992-03-24
•
Expires: 2010-11-16
Abstract
Abstract Disclosed is hylan, a chemically modified hyaluronan preparation characterized by the presence of small amounts (0.0002-0.05% by weight) of aldehyde cross-linking groups covalently bonded to the hyaluronan molecular chains. Also disclosed is an improved method of obtaining hylan comprising treating hyaluronan in situ in animal tissues containing same with a treatment mixture including an aldehyde which is reactive towards hyaluronic acid and the proteins contained in the animal tissue. Treatment is effected at temperatures below about 16° C. at very high pH, e.g., 8-14 whereby the overall yield is increased while maintaining the high molecular weight of the hylan.
Inventors
- 👤 Endre A. Balazs
- 👤 Adolf Leshchiner
- 👤 Adelya Leshchiner
- 👤 Nancy Larsen
- 👤 Philip Band
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:25
CPC Classifications
C; C08; C08B; C08B37/00; C08B37/006; C08B37/0063; C08B37/0072
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
133 words
A method of obtaining a chemically modified hyaluronic acid preparation comprising: (a) treating animal tissue containing hyaluronic acid with an aqueous treating mixture including an aldehyde to effect chemical modification of the hyaluronic acid contained in the tissue, in situ, (b) removing excess treating mixture from the reaction mixture, (c) extracting the chemically modified hyaluronic acid from the treated animal tissue with water at a temperature below about 16° C. and an alkaline pH of from 8 to 14 and beyond for about 6 hours to several days, the weight ratio of water to treated tissue being about 2-5:1 based on the weight of the treated tissue, (d) separating the extract containing the chemically modified hyaluronic acid from the treated animal tissue, and (e) recovering the chemically modified hyaluronic acid from the extract.
Claim 2
Independent Claim
133 words
A method of obtaining a chemically modified hyaluronic acid preparation comprising: (a) treating animal tissue containing hyaluronic acid with an aqueous treating mixture including an aldehyde to effect chemical modification of the hyaluronic acid contained in the tissue, in situ, (b) removing excess treating mixture from the reaction mixture, (c) extracting the chemically modified hyaluronic acid from the treated animal tissue with water at a temperature below about 16° C. and an alkaline pH of from 8 to 14 and beyond for about 6 hours to several days, the weight ratio of water to treated tissue being about 2-5:1 based on the weight of the treated tissue, (d) separating the extract containing the chemically modified hyaluronic acid from the treated animal tissue, and (e) recovering the chemically modified hyaluronic acid from the extract.
Claim 3
Dependent Claim
14 words
A method according to claim 1 wherein the temperature is below about 5° C.
Claim 4
Dependent Claim
22 words
A method according to claim 1 wherein the alkaline pH is achieved using an inorganic base, an organic base or mixtures thereof.
Claim 5
Dependent Claim
13 words
A method according to claim 3 wherein the base is an inorganic base.
Claim 6
Dependent Claim
22 words
A method according to claim 4 wherein the inorganic base is sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodium carbonate or potassium carbonate.
Claim 7
Dependent Claim
13 words
A method according to claim 3 wherein the base is an organic base.
Claim 8
Dependent Claim
14 words
A method according to claim 6 wherein the organic base is triethylamine or triethanolamine.
Claim 9
Dependent Claim
14 words
A method according to claim 1 wherein the aldehyde is formaldehyde, glutaraldehyde or glyoxal.
Claim 10
Dependent Claim
22 words
A method according to claim 1 wherein the aqueous treating mixture includes a water-miscible solvent which does not react with the aldehyde.
Claim 11
Dependent Claim
20 words
A method according to claim 9 wherein the solvent is a lower ketone, a lower alcohol or an aprotic solvent.
Claim 12
Dependent Claim
23 words
A method according to claim 10 wherein the solvent is acetone, methyl ethyl ketone, ethanol, isopropanol, dimethyl formamide, dimethyl acetamide or dimethyl sulfoxide.
Claim 13
Dependent Claim
31 words
A method according to claim 9 wherein the weight ratio of water to water-miscible solvent in the treating mixture is 1-5:4-8.5 and the weight ratio of water to aldehyde is 1-5:0.02-1.
Claim 14
Dependent Claim
21 words
A method according to claim 9 wherein the aqueous treating mixture optionally includes an electrolyte and a water insoluble organic solvent.
Claim 15
Dependent Claim
20 words
A method according to claim 13 wherein the electrolyte is sodium acetate and the water insoluble organic solvent is chloroform.
Claim 16
Dependent Claim
30 words
A method according to claim 12 wherein the treating mixture comprises, in parts by weight: ______________________________________
water 10-50
water-miscible solvent
40-85
aldehyde 0.2-10
water insoluble solvent
0.5-10
electrolyte 0-20
______________________________________
Claim 17
Dependent Claim
30 words
A method according to claim 1 wherein the weight ratio of treating mixture to tissue to be treated is at least 10:1, and treatment is effected for about 4-24 hours.
Claim 18
Dependent Claim
28 words
A method according to claim 1 wherein the animal tissue is rooster, chicken or hen combs and the combs are cut into slices of about 1-3 mm thickness.
Claim 19
Dependent Claim
28 words
A method according to claim 1 wherein excess treating mixture is removed from the reaction mixture by washing the treated tissue with a solvent or a solvent-water mixture.
Claim 20
Dependent Claim
26 words
A method according to claim 18 wherein the solvent used for washing the treated tissue is the same solvent as is used in the treating mixture.
Claim 21
Dependent Claim
23 words
A method according to claim 1 wherein the treated tissue is dried to about 25-50% of the treated weight before the extraction step.
Claim 22
Dependent Claim
14 words
A method according to claim 20 wherein drying is effected in air or nitrogen.
Claim 23
Dependent Claim
17 words
A method according to claim 1 wherein recovering is effected by precipitation with a quaternary ammonium compound.
Claim 24
Dependent Claim
15 words
A method according to claim 22 wherein the quaternary ammonium compound is cetyl pyridinium chloride.
Claim 25
Dependent Claim
20 words
A method according to claim 1 wherein the extract is separated from the animal tissue by filtration, centrifugation or decantation.
Claim 26
Dependent Claim
12 words
A method according to claim 24 wherein separation is effected by filtration.
Claim 27
Dependent Claim
40 words
A method according to claim 25 wherein the filtration is a two step procedure, a first, or gross filtration through a wide mesh to remove the pieces of animal tissue and a second, or fine filtration through a cellulosic material.
Claim 28
Dependent Claim
34 words
A method according to claim 1 wherein the chemically modified hyaluronic acid is recovered from the extract by precipitation with a solvent, followed by washing and drying the resulting precipitated chemically modified hyaluronic acid.
Claim 29
Dependent Claim
18 words
A method according to claim 27 wherein the solvent used for the precipitation is acetone, ethanol or isopropanol.
Claim 30
Dependent Claim
19 words
A method according to claim 28 wherein a mineral acid or an electrolyte is added during the precipitation step.
Claim 31
Dependent Claim
29 words
A method according to claim 29 wherein the mineral acid is HCl, H 2 SO 4 or H 3 PO 4 and the electrolyte is sodium acetate or NaCl.
Claim 32
Dependent Claim
19 words
A method according to claim 1 wherein the chemically modified hyaluronic acid is removed from the extract by lyophilization.
Claim 33
Dependent Claim
42 words
A method of cross-linking the chemically modified hyaluronic acid obtained according to the method of claim 1, which comprises subjecting said chemically modified hyaluronic acid to a cross-linking reaction with divinyl sulfone under alkaline conditions at room temperature for about one hour.
Claim 34
Dependent Claim
56 words
A method according to claim 1 and further comprising, washing said animal tissue in an uncut state with an inorganic alkali in an amount and concentration sufficient to create a pH of more than 12 for about 5 minutes to several hours, prior to the step of treating the animal tissue with the aqueous treating mixture.
Claim 35
Dependent Claim
19 words
A method according to claim 33 wherein the inorganic alkali is NaOH at a concentration of 0.05M to 4M.
Claim 36
Dependent Claim
37 words
A method according to claim 1 and further comprising neutralizing the excess alkali used in the extracting step by adding an acid to thereby render the preparation suitable for use in products requiring a substantially neutral pH.
Claim 37
Dependent Claim
16 words
A method according to claim 35 wherein the acid is an inorganic, organic or polymeric acid.
Claim 38
Dependent Claim
24 words
A method according to claim 36 wherein the acid is inorganic and is HCl, H 2 SO 4 or H 3 PO 4 .
Claim 39
Dependent Claim
21 words
A method according to claim 36 wherein the acid is organic and is acetic, citric, stearic, palmitic, lauric, or p-aminobenzoic acid.
Claim 40
Dependent Claim
28 words
A method according to claim 36 wherein the acid is polymeric and is poly acrylic acid, poly methracylic acid, poly vinyl sulfonic acid or poly styrene sulfonic acid.
Claim 41
Dependent Claim
14 words
A cosmetic formulation containing a preparation obtained according to the method of claim 35.
Claim 42
Dependent Claim
10 words
A product produced by the method according to claim 1.
Claim 43
Dependent Claim
10 words
A product produced by the method according to claim 33.
Claim 44
Dependent Claim
11 words
A cross-linked product produced by the method according to claim 32.
Claim 45
Dependent Claim
29 words
A chemically modified hyaluronic acid preparation characterized by the presence of about 0.0002 to 0.05% by weight of aldehyde cross-linking groups covalently bonded to the hyaluronic acid polymer chains.
Claim 46
Dependent Claim
29 words
A chemically modified hyaluronic acid preparation characterized by the presence of about 0.0002 to 0.05% by weight of aldehyde cross-linking groups covalently bonded to the hyaluronic acid polymer chains.
Claim 47
Dependent Claim
12 words
A preparation according to claim 44 which is sterile, non-inflammatory and pyrogen-free.
References Cited (Backward Citations)
US3396081A
Cited
US4141973A
Cited
US4141973B1
Cited
US4272522A
Cited
US4303676A
Cited
US4517295A
Cited
US4487865A
Cited
US4500676A
Cited
US4629623A
Cited
US4582865A
Cited
US4605691A
Cited
US4713448A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-24 | 1995-09-23 | 1996-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-24 | 1999-09-23 | 2000-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-24 | 2003-09-23 | 2004-03-24 | $7700.00 | Window Closed / Lapsed |