In one embodiment, a method of filling a container with a liquid drug from a drug reservoir may include: a) connecting a container and a drug reservoir with a cannula such that the drug reservoir and the container fluidically communicate with each other via the cannula, while being hermetically sealed； b) reducing a first volume contained within the container to displace a gaseous medium from the first volume of the container via the cannula into a second volume contained within the drug reservoir； c) increasing the first volume of the container to displace the liquid drug from the second volume of the drug reservoir into the first volume of the container to fill the container； and d) disconnecting the container and the drug reservoir. Before performing action d), action b) and action c) can be successively performed more than once to stepwise increase an amount of liquid drug displaced.
