A device is disclosed for reconstitution and delivery of an injectable pharmaceutical. A pharmaceutical composition such as a lyophilized drug is provided in a pressurizable fluid reservoir with a pierceable seal. A diluent may be separately provided in a syringe with a needle. When the needle is driven through the seal and the plunger is actuated, fluid from the barrel of the syringe flows into the pressurizable fluid reservoir to simultaneously pressurize the reservoir and mix the diluent with the drug. Pressurized in this manner, the reservoir can then automatically and without further user intervention push the mixture back through the needle and into the barrel of the syringe, further mixing the composition and displacing the plunger to fill the barrel with the reconstituted drug. The needle and syringe can then be detached from the reservoir with the reconstituted drug contained in the barrel and ready for injection.
