Abstract: A method for obtaining solutions of non-structurally modified salts of alginate, with endotoxin content less than 20 EU/g includes obtaining an alginate solution having a concentration ranging from 1.6 to 2.0% by weight by adding commercial grade alginate powder to a saline solution. The alginate solution obtained is filtered on at least one hydrophilic filter, and a filtered alginate solution is recovered. The filtered alginate solution obtained is further filtered on a charge-modified hydrophobic filter, and an alginate solution having an endotoxin content less than 20 EU/g is recovered.