Safety capsule for a container

A closure capsule for closing a container, comprising: a cap (2) to be associated with the container and comprising a frangible mouth (20); a cutter (3) for opening said frangible mouth (20); a covering (4) protecting said cap (2) and said cutter (3) and comprising an intactness band (40); first toothed connection means (5) afforded on the covering (4) and on the cutter (3) and that make said cutter (3) and said covering (4) rotate integrally. The closure capsule is movable from a initial configuration to an operative configuration, wherein the intactness band is removed and the frangible mouth is broken. In the initial configuration, the cap, the cutter and the covering contribute to the definition of walls of a reservoir (8) for containing a product to be dropped into the container in the operative configuration.