Liquid drug delivery device includes a housing with a syringe port for sealingly receiving a syringe having a syringe tip ending at a widened distal tip, a vial adapter port with a vial adapter for snap fit receiving a vial, and a drug administration port for administering a liquid drug. The vial adapter is intended to be rotationally detached after a mixing procedure for discarding together with a spent vial. The syringe port additionally includes a single use locking mechanism for securing the syringe to preclude inadvertent syringe detachment under normal use including agitation for reconstitution purposes. The drug administration port has a distal tip preferably similar to a syringe's widened distal tip for the same purpose of preventing conventional needles with a female Luer connector being slidingly mounted thereon.