Abstract: The present disclosure provides a method for manufacturing an auto-crosslinked hyaluronic acid gel, comprising conducting auto-crosslinking reaction of a colloid containing hyaluronic acid continuously at low temperature in an acidic environment, and treating the reaction product with steam at high temperature to obtain the auto-crosslinked hyaluronic acid gel with high viscosity.

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.

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.

Abstract: A method for producing cross-linked hyaluronic acid has cross-linking one or more polymers at a low temperature from 10 to 30° C. for a reaction time greater than 48 hours under basic condition with a cross-linking agent to form a cross-linked hyaluronic acid, wherein the polymer is selected from the group consisting of hyaluronic acid, hyaluronate, derivatives thereof and a mixture thereof. Whereby, a cross-linking agent content in a product of the method is decreased so the product does not require purification.