An apparatus for removal of premixed drugs or reconstitution of lyophilized drugs and for the injection of the reconstituted drug into the patient. The apparatus includes a syringe assembly and an adapter assembly that can be removably connected to a medicament container containing a premixed drug or lyophilized medicament. The syringe assembly of the apparatus includes a liquid chamber between the forward end of the body portion and the piston and a syringe cannula assembly. The syringe cannula assembly, which can be removably interconnected with the body portion, comprises a cannula support and a hypodermic needle sealably connected to the cannula support. The adapter assembly comprises an adapter preferably molded from a moldable plastic that includes a top wall, an adapter cannula connected to and extending from the top wall and a variety of connectors connected to the top wall for removably interconnecting the adapter with the medicament container. The adapter assembly further includes syringe connector member connected to the top wall for removably interconnecting the syringe with the adapter in a manner to uniquely position the syringe cannula within the lumen of the adapter cannula wherein it is completely shielded from external contamination to prevent print damage and injury to the user.