In one aspect, the subject invention is directed to a method of preparing a combinatorial drug delivery device based on a predetermined selection of drug components. The method includes: preparing a plurality of containers, each accommodating one of the selected drug components; coupling the containers to a common outlet so that the drug components may be extracted from the containers and dispensed through the common outlet; and, applying negative pressure to extract the drug components from the containers and urge the drug components towards the common outlet.