The invention provides a composition comprising an aqueous solution of 0.1-20 wt. % of a poly(amine) and 0.1 to 50 wt. % of a carboxylated carbohydrate having an average molecular weight of at least 100,000 D and a degree of carboxyl substitution of at least 5%, which carboxylated carbohydrate has been obtained by subjecting a corresponding original carbohydrate to an oxidation treatment whereby carboxyl and aldehyde groups are obtained by oxidation of hydroxyl groups of the original carbohydrate, after which the oxidised carbohydrate so obtained is contacted with a reducing agent whereby at least part of the aldehyde groups that were obtained in the oxidation treatment are reduced to hydroxymethyl groups, whereby the carboxylated carbohydrate comprises at least part of the reducing agent and/or its reaction product(s), and wherein the carboxylated carbohydrate forms a complex with the poly(amine).