The present invention relates to a method for preparing a surgical anti-adhesion barrier film comprising the following steps:a°) a first solution, comprising an oxidized collagen is prepared,b) a polyphosphate compound is added to the solution of a) in a quantity so as to obtain a concentration of polyphosphate ranging from 0.007 to 0.7%, by weight, with respect to the total weight of the solution,c) the pH of the solution obtained in b) is adjusted to about 9 by addition of a base or to about 5.1 by addition of an acid,d) a diluted solution is prepared by adding water to solution of c),e) a first layer of solution obtained in c) is casted on an inert support,f) before complete gelation of the layer obtained in d), a second layer, of diluted solution obtained in d) is applied on top of said first layer and let to gelify,g) the gelified first and second layers are dried to obtain a film.The invention further relates to a film obtainable by such a method and to a surgical implant comprising a prosthetic fabric and such a film.
