A medication delivery device (10), comprising: a needle cannula (16), which has a sharp distal end having a leading tip (34)； a barrel (26), which has open proximal and distal ends and that has a reservoir (28) defined between them, such that said needle cannula (16) is disposed at said open distal end of said barrel (26) and it is in fluid communication with said reservoir (28), and a limiting element (12), arranged around said needle cannula (16) and having a distal end defining a surface (20) of engagement with the skin, arranged transversely to said needle cannula (16) and at least partially around it, such that said skin-engaging surface (20) has generally coplanar portions (25), such that said front tip (34) of said needle cannula (16) is separated from a plane defined by said coplanar portions in a distance ranging from about 0.5 mm to 3.0 mm, such that said skin engagement surface (20) limits the penetration of said front tip (34) of said needle cannula (16) to the dermis layer of the patient's skin, characterized in that said skin engaging surface (20) includes a secondary surface portion (134) and an annular projection (134) extending distally from said secondary surface portion, so it is not flat, said annular projection (130) has a polygonal cross section defining said generally coplanar portions (25), and said projection (130) has a height (h) that it oscillates between 0.2 and 1.0 mm, so that said projection ends at a free distal end (132), so that said free distal end defines a width (w) ranging between 0.2 mm and 0.6 mmUn dispositivo (10) de aporte de medicación, que comprende: una cánula (16) de aguja, que tiene un extremo distal aguzado que tiene una punta delantera (34)； un barril (26), que tiene extremos proximal y distal abiertos y que tiene un depósito (28) definido entre ellos, de tal manera que dicha cánula (16) de aguja está dispuesta en dicho extremo distal abierto de dicho barril (26) y está en comunicación de fluido con dicho depósito (28
