A method of preparing a body-wearable combinatorial drug delivery device (200, 300, 400, 500, 600, 700) for delivering drug to a patient based on a predetermined selection of drug components (216, 310, 420, 516, 616, 710) accommodated by a plurality of discrete containers (214, 308, 418, 514, 614, 708), the method characterized by: providing a wearable device (200, 300, 400, 500, 600, 700) having an adhesive patch, for adhering to the skin of the patient, or a mounting belt (626, 718), for supporting the device (200, 300, 400, 500, 600, 700) on the body of the patient, the wearable device (200, 600, 400, 500, 600, 700) including containers (214, 308, 418, 514, 614, 708) coupled to a common outlet (222, 314, 426, 520, 624, 716), the common outlet (222, 314, 426, 520, 624, 716) being in communication with each of the coupled containers (214, 308, 418, 514, 614, 708) through a common flow path so that the drug components (216, 310, 420, 516, 616, 710) may be extracted from the coupled containers (214, 308, 418, 514, 614, 708) and dispensed through the common outlet (222, 314, 426, 520, 624, 716); and, the wearable device configured for applying negative pressure to the common outlet (222, 314, 426, 520, 624, 716) by a pump (208, 306, 410, 510, 608, 706), externally of the coupled containers (214, 308, 418, 514, 614, 708), to extract the drug components (216, 310, 420, 516, 616, 710) from the containers (214, 308, 418, 514, 614, 708) and urge the drug components (216, 310, 420, 516, 616, 710) towards the common outlet (222, 314, 426, 520, 624, 716), wherein, the pump (208, 306, 410, 510, 608, 706), the coupled containers (214, 308, 418, 514, 614, 708), and at least a portion of the common outlet (222, 314, 426, 520, 624, 716) are fully housed within the wearable device (200, 300, 400, 500, 600, 700). providing a wearable device (200, 300, 400, 500, 600, 700) having an adhesive patch, for adhering to the skin of the patient, or a mounting belt (626, 718), for supporting the device (200, 300, 400, 500, 600, 700) on the body of the patient, the wearable device (200, 600, 400, 500, 600, 700) including containers (214, 308, 418, 514, 614, 708) coupled to a common outlet (222, 314, 426, 520, 624, 716), the common outlet (222, 314, 426, 520, 624, 716) being in communication with each of the coupled containers (214, 308, 418, 514, 614, 708) through a common flow path so that the drug components (216, 310, 420, 516, 616, 710) may be extracted from the coupled containers (214, 308, 418, 514, 614, 708) and dispensed through the common outlet (222, 314, 426, 520, 624, 716); and, the wearable device configured for applying negative pressure to the common outlet (222, 314, 426, 520, 624, 716) by a pump (208, 306, 410, 510, 608, 706), externally of the coupled containers (214, 308, 418, 514, 614, 708), to extract the drug components (216, 310, 420, 516, 616, 710) from the containers (214, 308, 418, 514, 614, 708) and urge the drug components (216, 310, 420, 516, 616, 710) towards the common outlet (222, 314, 426, 520, 624, 716), wherein, the pump (208, 306, 410, 510, 608, 706), the coupled containers (214, 308, 418, 514, 614, 708), and at least a portion of the common outlet (222, 314, 426, 520, 624, 716) are fully housed within the wearable device (200, 300, 400, 500, 600, 700).