A tip cover designed to be hermetically mounted on a tip (27) protruding distally from an injection device (20) having a conduit extending therethrough, the tip cover (1) having an axis (2) and comprising: - a closed distal end portion (3) having a substantially transverse proximal surface (5)； - a substantially cylindrical peripheral skirt (7) extending in the proximal direction from the proximal surface (5) of the distal end portion (3), said peripheral skirt (7) having an internal surface (10) designed to cooperate with the outer surface (31) of the tip (27) of the injection device； - a nozzle (11) protruding from the proximal surface (5) of the distal end portion (3) in the proximal direction, said nozzle (11) having a dome-shaped proximal portion (13) designed to engage the tip (27) of the injection device； thus forming an internal cavity (14) in the tip cover (1), the bottom (15) of said cavity (14) being part of the proximal surface (5) of the distal end portion (3) and having a shape substantially annular which is connected to the inner surface (10) of the peripheral skirt by an outer fillet (16) and to the nozzle (11) by an internal fillet (17), characterized in that: - the outer fillet (16) has a radius (R16) of curvature ranging from 0.4 to 0.6 mm； - the internal fillet (17) has a radius (R17) of curvature ranging from 0.25 to 0.35 mm； - the width (W) of the nozzle base, substantially in the plane of the proximal surface (5) of the distal end portion (3), varies from 1.4 to 1.6 mm； - the proximal dome-shaped portion (13) of the nozzle (11) has a radius (R13) of curvature ranging from 0.55 to 0.70 mm.Una tapa de punta diseñada para ser montada herméticamente en una punta (27) que sobresale distalmente de un dispositivo (20) de inyección que tiene un conducto que se extiende a su través, teniendo la tapa (1) de punta un eje (2) y que comprende: - una porción (3) de extremo distal cerrada que tiene una superficie (5) proximal sustancialmente transversal； - u
