It is described a cartridge (10) for injecting a pharmaceutical solution, including at least one flexible small bag (18, 22), being made of thin film walls, having a chamber (12, 14) containing a pharmaceutical substance (S, P, L) and having a head surface (37) being outwardly convex. It is also described a syringe (100) for injecting a pharmaceutical solution (S), including a body (102) being extended along a main axis (X) and provided with an accommodating space (120) to accommodate a cartridge (10), and a plunger (110) being provided with a head (113) being dome-shaped and convex towards the space (120), preferably asymmetrical with respect to the main axis (X). Furthermore, it is described an injection kit for injecting a pharmaceutical solution, including a syringe (100) and at least one cartridge (100).
