A method for preparing a water-insoluble water-absorbing adhesive composition comprising combining, under conditions effective to form a homogeneous mixture: a) a hydrophilic film-forming polymer comprising at least one linear segment containing a plurality of polar groups recurring; b) a complementary multifunctional polymer containing a plurality of recurring functional groups along the main polymer chain, said recurring functional groups being capable of non-covalently joining the recurring polar groups in such a way that an interpolymer complex is formed ladder type between the at least one linear segment and the complementary multifunctional polymer; and c) a plasticizer capable of plasticizing the film-forming polymer, in which the weight fraction of the film-forming polymer in the mixture is greater than the weight fraction of the complementary multifunctional polymer or plasticizer; characterized in that: i) the hydrophilic film-forming polymer is selected from poly (dialkylaminoalkyl acrylates), poly (dialkylaminoalkyl methacrylates), poly (N, N-dialkylacrylamides), poly (trimethylammonioethyl methacrylate), poly (N-vinyl lactams), copolymers thereof, and combinations of any of the foregoing; and ii) the complementary multifunctional polymer is selected from poly (acrylic acid), poly (methacrylic acid), poly (maleic acid), poly (hydroxyalkyl methacrylates), cellulose derivatives, copolymers thereof, and combinations of any of the previous; or i) the film-forming hydrophilic polymer is selected from poly (acrylic acid), poly (methacrylic acid), poly (maleic acid), poly (hydroxyalkyl methacrylates), cellulose derivatives, copolymers thereof, and combinations of any of the previous ones; and ii) the complementary multifunctional polymer is selected from poly (dialkylaminoalkyl acrylates), poly (dialkylaminoalkyl methacrylates), poly (N, N-dialkylacrylamides), poly (trimethylammonioethyl methacrylate), poly (N-vinyl lactams), copolymers of the same, and combina