Abstract: A pressurized additive transfer device for storing and transferring of a fluid material to a solution container such as a rigid container or an I.V. bag having an exposed pierceable closure or port. The transfer device is self-pressurized and includes a closure with channel portions to permit the introduction of a pressurizing media. The closure also has a central opening in alignment with a pierceable diaphragm. A piercing member having a double pointed end is disposed in the central opening which affords a movement of the piercing member toward the pierceable diaphragm to pierce it. Frictional engagement elements are provided between the piercing member and the central opening to hold the piercing member when it punctures the diaphragm as well as the solution container closure or port. In one embodiment, a vent slot is provided in the piercing member to serve as a vent for the solution container.