Fluid transfer device connecting a medicinal vessel and an IV bag in closed system

A fluid transfer device connecting a medicinal vessel and an intravenous (IV) bag for enabling the mixing in closed system of the two products contained therein, comprising a three-way plug valve assembly (3) with a first port, provided along the rotation axis of said valve (3), ending in a connector (5) for a syringe, and a second and a third port (8, 7) opposite to each other and both orthogonal to said first port, each one provided into a respective spike (1, 2) connected to a housing (16, 17) for a container of medicinal product, the said valve (3) being so shaped as to alternatively connect said first port with said second port (8) or with said third port (7), wherein within the first one of the said two spikes (1) a further independent channel (13) is provided for the inlet and the outlet of air, communicating with the external environment through a hydrophobic filter (14) included in the device, characterised in that the second one of said two spikes (2) is capable of piercing the rubber closure of the injection point of a bag of medicinal product, and in that the housing (17) provided on said second spike (2) consists of two flexible arms (18, 19) attached to the device close to the point where the said second spike (2) is connected to the device, said arms (18, 19) extending substantially parallel to said second spike (2) and being fastenable to each other at the respective ends, so as to be tightened around the tube of the said injection point.