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US5484913A
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Calcium-modified oxidized cellulose hemostat
Assignee: Ethicon Inc
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Filing: 1995-03-24
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Granted: 1996-01-16
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Expires: 2015-03-24
Abstract
Abstract A calcium-modified oxidized cellulose hemostat provides faster hemostasis than does either unmodified or sodium- or potassium-modified oxidized cellulose. The percentage by weight of calcium in the modified oxidized cellulose must be in a range between about 0.5 and about 4, in order to enhance hemostasis, while not interfering excessively with bioabsorbability. In a second embodiment, an oxidized cellulose hemostat is modified with both calcium and either sodium or potassium. The second embodiment may be used to deliver acid-sensitive materials.
Inventors
- 👤 Reginald L. Stilwell
- 👤 Elaine J. Whitmore
- 👤 Lowell G. Saferstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:20
CPC Classifications
A; A61; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/64; A61L15/22; A61L15/28; A61P; A61P7/00; A61P7/04; C; C08; C08L; C08L1/00; C08L1/02; C08L1/04; A61L2400/00; A61L2400/04; Y; Y10; Y10S; Y10S602/00; Y10S602/90
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
18 words
A bioabsorbable surgical hemostat comprising a neutralized oxidized cellulose fabric comprising between about 0.5% and about 4.0% calcium.
Claim 2
Dependent Claim
18 words
A bioabsorbable surgical hemostat comprising a neutralized oxidized cellulose fabric comprising between about 0.5% and about 4.0% calcium.
Claim 3
Dependent Claim
18 words
The surgical hemostat of claim 1 in which the fabric comprises between about 2.0% and about 3.5% calcium.
Claim 4
Dependent Claim
16 words
The surgical hemostat of claim 1, further comprising about 2% to about 6% sodium or potassium.
Claim 5
Dependent Claim
13 words
The surgical hemostat of claim 3, further comprising a hemostatic-effective amount of thrombin.
Claim 6
Dependent Claim
77 words
A process for preparing a bioabsorbable surgical hemostat comprising the steps of: (a) contacting an oxidized cellulose material that contains a predetermined concentration of carboxylic acid with a sufficient quantity of a chloride-free solution of a calcium salt of a weak acid to neutralize about 5.5% to about 45% of the carboxylic acid and provide a calcium content in the fabric of between about 0.5% and about 4.0%; and (b) washing the material to remove excess salt.
Claim 7
Dependent Claim
77 words
A process for preparing a bioabsorbable surgical hemostat comprising the steps of: (a) contacting an oxidized cellulose material that contains a predetermined concentration of carboxylic acid with a sufficient quantity of a chloride-free solution of a calcium salt of a weak acid to neutralize about 5.5% to about 45% of the carboxylic acid and provide a calcium content in the fabric of between about 0.5% and about 4.0%; and (b) washing the material to remove excess salt.
Claim 8
Dependent Claim
110 words
A process for preparing a bioabsorbable surgical hemostat comprising the steps of: (a) contacting an oxidized cellulose material that contains a predetermined concentration of carboxylic acid with a sufficient quantity of a chloride-free solution of a calcium salt of a weak acid and a quantity of a sodium or potassium salt of a weak acid to neutralize about 50% to about 80% of the carboxylic acid, with the calcium neutralizing about 5.5% to about 45% of the acid the sodium or potassium salt neutralizing the balance, and providing a calcium content in the fabric of between about 0.5% and about 4.0%; and (b) washing the material to remove excess salt.
Claim 9
Dependent Claim
110 words
A process for preparing a bioabsorbable surgical hemostat comprising the steps of: (a) contacting an oxidized cellulose material that contains a predetermined concentration of carboxylic acid with a sufficient quantity of a chloride-free solution of a calcium salt of a weak acid and a quantity of a sodium or potassium salt of a weak acid to neutralize about 50% to about 80% of the carboxylic acid, with the calcium neutralizing about 5.5% to about 45% of the acid the sodium or potassium salt neutralizing the balance, and providing a calcium content in the fabric of between about 0.5% and about 4.0%; and (b) washing the material to remove excess salt.
Claim 10
Dependent Claim
20 words
The process of claim 6 including the additional step of impregnating the dried material with a hemostatic-effective amount of thrombin.
Claim 11
Dependent Claim
16 words
The surgical hemostat of claim 3 wherein the fabric comprises between about 2% and 3.5% calcium.
Claim 12
Dependent Claim
16 words
The surgical hemostat of claim 8 wherein the fabric has a pH between 5.0 and 8.0.
Claim 13
Dependent Claim
16 words
The surgical hemostat of claim 9 wherein the fabric has a pH between 6.5 and 7.0.
Claim 14
Dependent Claim
13 words
The surgical hemostat of claim 10, further comprising a hemostatic-effective amount of thrombin.
Claim 15
Dependent Claim
33 words
The process according to claim 5 wherein the quantitiy and molarity of the calcium salt of a weak acid is determined prior to the step of contacting it with the oxidized cellulose material.
Claim 16
Dependent Claim
18 words
The process according to claim 5 wherein the calcium salt of a weak acid comprises calcium acetate monohydrate.
Claim 17
Dependent Claim
32 words
The process according to claim 5 wherein the calcium salt of a weak acid is added in a quantity to provide a calcium content in the fabric of between 2% and 3.5%.
Claim 18
Dependent Claim
26 words
The process according to claim 6 and further comprising the step of impregnating the material with a therapuetically effective amount of an acid sensitive therapuetic agent.
Claim 19
Dependent Claim
24 words
The process of claim 15 wherein the therapuetic agent is selected from the group comprising: thrombin, tissue plasminogen activator analogue, fibrinogen or an antifibrinolytic.
Claim 20
Dependent Claim
11 words
The process of claim 16 wherein the therapeutic agent comprises thrombin.
References Cited (Backward Citations)
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