The present invention relates to a method of making a composition, the composition comprising a cross-linked polymer and water, comprising at least the following steps: a) providing a first mixture, comprising at least one polymer and an aqueous alkaline solution b) generating a gel by cross-linking the at least one polymer with a cross-linking agent c) neutralizing the generated gel by using a neutralization solution d) optionally adding a second mixture, comprising a cross-linked and/or non-cross-linked polymer and water, to the neutralized gel obtained in step c) e) dialyzing the gel obtained in step d) or dialyzing the gel obtained in step c) and optionally subsequent addition of the second mixture, comprising a cross-linked and/or non-cross-linked polymer and water and f) filling the dialyzed gel obtained in step e) into a container, wherein at least two or three or four or five or all of steps a) to f) are automated.
