A biodegradable film (4) characterized in that it is prepared from at least one co-product derived from a soya bean-processing process aimed at obtaining soya-based final products by ultrafiltration, said co-product being selected from the group comprising the okara and the permeate. Such a film can be used as a food or pharmaceutical film, in particular for preparing a product for topical administration (1) of a pharmaceutical active ingredient, such as oestrogens.
