Method for preparing an anti-adhesion barrier film

A method for preparing a surgical anti-adhesion barrier film comprising

• a) preparing a first solution comprising oxidized collagen at a concentration ranging from 0.5% to 6% by weight, with respect to a total weight of the first solution,
• b) adding a polyphosphate compound to the first solution 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 first solution,
• c) adjusting a pH of the first solution obtained in b) to about 9 by adding a base or to about 5.1 by adding an acid,
• d) adding water to the first solution of c) to form a diluted solution having a concentration of oxidized collagen ranging from 0.1% to 2.7% by weight, with respect to the diluted solution,
• e) casting a first layer of the first solution obtained in c) at a basis weight ranging from 0.03 to 0.4 g/cm2,
• f) applying a second layer of the diluted solution obtained in d) on top of the first layer at a basis weight ranging from 0.03 to 0.4 g/cm2 before complete gelation of the first layer obtained in e), and let gelify,
• g) drying the first and second layers to obtain a film.