Lyophilized drugs are stored in vials, cartridges, dual chamber syringes, and prefilled mixing systems.
Lyophilization, or freeze drying, is a process that removes water from a liquid drug creating a solid powder, or cake. The lyophilized product is stable for extended periods of time and could allow storage at higher temperatures. In protein formulations, stabilizers are added to replace the water and preserve the structure of the molecule.
Before administration, a lyophilized drug is reconstituted as a liquid before being administered. This is done by combining a liquid diluent with the freeze-dried powder, mixing, then injecting.  Reconstitution usually requires a reconstitution and delivery system to ensure that the drug is correctly mixed and administered.