A device for injecting a reconstitutable liquid mixture, comprising: - a first containment chamber for a first component of the liquid mixture; - at least a second containment chamber for a second component of the liquid mixture, - first mechanical and fluidic connection means (43,33) between said first and said second containment chambers; - second mechanical and fluidic connection means between said second containment chamber and an injection needle; the device being characterized in that: - said first containment chamber comprises, along a mixture injection direction (y), a first upper surface and a first lower surface, in the shape of a cone or truncated cone, substantially having the same axis of symmetry and a common base circumference; - said first upper surface and said first lower surface have extensions in opposite directions along said axis of symmetry and form a non-zero angle β therebetween at the common base; - said second containment chamber comprises, along said mixture injection direction (y), a second upper surface and a second lower surface, in the shape of a cone or truncated cone, both substantially having said axis of symmetry and a common base circumference, - said second upper surface and said second lower surface have extensions in opposite directions along said axis of symmetry and form a non-zero angle α therebetween at the common base; - said first lower surface and said second lower surface are separately deformable by compression; and in that: - said first mechanical and fluidic connection means (43,33) comprise an outlet neck of said first containment chamber and an inlet neck of said second containment chamber connected to form a single fluidic connection duct; and - said single fluidic connection duct is such as to keep said first lower surface and said second lower surface at a distance configured to be larger than the section of a finger; wherein: - said first lower surface and said second lower surface are made of an inelastically deformable material; - said inelastically deformable material is such as to allow a total crushing of said first lower surface and said second lower surface against said first upper surface and second upper surface, respectively. - a first containment chamber for a first component of the liquid mixture; - at least a second containment chamber for a second component of the liquid mixture, - first mechanical and fluidic connection means (43,33) between said first and said second containment chambers; - second mechanical and fluidic connection means between said second containment chamber and an injection needle; - said first containment chamber comprises, along a mixture injection direction (y), a first upper surface and a first lower surface, in the shape of a cone or truncated cone, substantially having the same axis of symmetry and a common base circumference; - said first upper surface and said first lower surface have extensions in opposite directions along said axis of symmetry and form a non-zero angle β therebetween at the common base; - said second containment chamber comprises, along said mixture injection direction (y), a second upper surface and a second lower surface, in the shape of a cone or truncated cone, both substantially having said axis of symmetry and a common base circumference, - said second upper surface and said second lower surface have extensions in opposite directions along said axis of symmetry and form a non-zero angle α therebetween at the common base; - said first lower surface and said second lower surface are separately deformable by compression; - said first mechanical and fluidic connection means (43,33) comprise an outlet neck of said first containment chamber and an inlet neck of said second containment chamber connected to form a single fluidic connection duct; and - said single fluidic connection duct is such as to keep said first lower surface and said second lower surface at a distance configured to be larger than the section of a finger; - said first lower surface and said second lower surface are made of an inelastically deformable material; - said inelastically deformable material is such as to allow a total crushing of said first lower surface and said second lower surface against said first upper surface and second upper surface, respectively.