A method for combining a first liquid component with a second lyo component in a drug mixing apparatus is provided. The method comprises displacing a seal that prevents the first liquid component within a first barrel from coming into contact with the second lyo/liquid component within a second barrel. The method also comprises using an activating mechanism to move the first liquid component from the first barrel through at least one communication channel to an area within the second barrel holding the second lyo component, allowing the first liquid component to mix with the second lyo component to form a medicament. Additionally the method comprises displacing a second seal that prevents a medicament from entering an outlet channel. The method also comprises using the activating mechanism to eject the mixed medicament from the drug mixing apparatus through the outlet channel.
