Loth, F.F.Loth2022-03-082022-03-081998https://publica.fraunhofer.de/handle/publica/304052Recovery of hyaluronic acid by precipitation from a polyelectrolyte complex comprises reacting a hyaluronic acid-containing fermentation solution or brew with at least one equivalent of a chitosan salt solution. The resulting hyaluronic acid-chitosan complex is separated out and treated with aqueous alkali, the insoluble chitosan is separated off and the hyaluronic acid alkali salt is precipitated out from the alkaline or neutral solution before being washed and dried. USE - Hyaluronic acid is used in the pharmaceutical, medical and cosmetic industries. ADVANTAGE - The process avoids complexing hyaluronic acid with cationic detergents (e.g. cetyltrimethylammonium or cetylpyridinium salts) which are extremely difficult to remove, resulting in poor product quality. The detergents cannot be recycled and must be pumped out as waste, resulting in environmental damage. The hyaluronic acid obtained is of sufficient quality and purity for cosmetic and medical use.de608668patent1997-19712931