US Patent 11866556 Process for efficient cross-linking of hyaluronic acid

A process for manufacturing a cross-linked hyaluronic acid (HA) gel product is comprising the steps of: (a) preparing an aqueous mixture of HA and a cross-linking agent selected from multiepoxides and diepoxides; wherein the HA is dissolved in an aqueous solution containing 1-10% (w/w) inorganic hydroxide; and wherein the dissolved HA constitutes more than 10% (w/w) of the final mixture; and (b) subjecting the aqueous mixture to cross-linking conditions to allow the dissolved HA to react with the cross-linking agent so as to obtain a cross-linked HA gel product.