A syringe adapter element for use in a drug mixing system including a housing element having a syringe port adapted for fluid connection with a syringe and a fluid port adapted for fluid connection with a fluid flow adapter element, a needle and at least one septum disposed in the housing element, the needle having a sealed orientation wherein the at least one septum blocks fluid flow through the needle and a fluid flow orientation wherein the needle punctures the at least one septum so as to permit fluid to flow through the needle, and an anti-separation device adjacent the fluid port, such that when the syringe adapter element is connected to a fluid flow adapter element, the anti-separation device applies a force that acts against separating the syringe adapter element from the fluid flow adapter element.