METHOD FOR PRODUCING CROSS-LINKED HYALURONIC ACID
First Claim
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1. A method for producing a cross-linked hyaluronic acid comprising:
- (a) cross-linking at least one polymer at a temperature, from about 35°
C. to about 60°
C., for a reaction time of from about 0.1 hour to about 72 hours with a cross-linking agent; and
(b) lowering the temperature in step (a) to from about 10°
C. to about 30°
C. for a reaction time of from about 48 hours to about 28 days to obtain the cross-linked hyaluronic acid,wherein the steps (a) and (b) are conducted under a basic condition;
the polymer is selected from the group consisting of hyaluronic acid, hyaluronate, carboxymethylcellulous (CMC), alginate, chondroitin-4-sulfate, chondroitin-6-sulfate, xanthane gum, chitosan, pectin, agar, carrageenan and guar gum thereof and a mixture thereof; and
the method is absent a step of purifying the cross-linked hyaluronic acid and the content of the cross-linking agent with free-state functional group is below about 300 ppm in the cross-linked hyaluronic acid.
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Abstract
A method for producing a cross-linked hyaluronic acid in accordance with the present invention comprises: (a) cross-linking at least one polymer at a temperature, from about 35° C. to about 60° C., for a reaction time of from about 0.1 hour to about 72 hours with a cross-linking agent; and (b) lowering the temperature in step (a) to form about 10° C. to about 30° C. for a reaction time of from about 48 hours to about 28 days to obtain the cross-linked hyaluronic acid, whereby, a cross-linking agent content in a product of the method can be decreased so the product does not require purification.
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20 Claims
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1. A method for producing a cross-linked hyaluronic acid comprising:
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(a) cross-linking at least one polymer at a temperature, from about 35°
C. to about 60°
C., for a reaction time of from about 0.1 hour to about 72 hours with a cross-linking agent; and(b) lowering the temperature in step (a) to from about 10°
C. to about 30°
C. for a reaction time of from about 48 hours to about 28 days to obtain the cross-linked hyaluronic acid,wherein the steps (a) and (b) are conducted under a basic condition; the polymer is selected from the group consisting of hyaluronic acid, hyaluronate, carboxymethylcellulous (CMC), alginate, chondroitin-4-sulfate, chondroitin-6-sulfate, xanthane gum, chitosan, pectin, agar, carrageenan and guar gum thereof and a mixture thereof; and the method is absent a step of purifying the cross-linked hyaluronic acid and the content of the cross-linking agent with free-state functional group is below about 300 ppm in the cross-linked hyaluronic acid. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification