A vial adapter element for use ina drug mixing system including a body, a vialconnection port extending from the body, a hol-lowvial puncturing spike that protrudes into thevial connection port and is in fluid communica-tionwith a syringe-adapter-element connectionport that extends from the body, and a pluralityof resilient tongues spaced around an inner wallof the body, the tongues being located in gapsformed in the inner wall of the body.
