A medicament-dispensing system includes a cartridge for housing and actuating an accordion-like vial-dispenser for dispensing a calibrated amount of medicament by means of a single actuation motion which sequentially loads the vial-dispenser and dispenses the loaded medicament. The vial-dispenser has a front bellows portion, a rear bellows portion, an internal piston mechanism, a medicament storage chamber and a dosage cavity. The cartridge has a trigger mechanism which acts in concert with a notched lever and a wedge-shaped arm internally located in the cartridge to sequentially load the dosage cavity with medicament and discharge it. Depression of the trigger mechanism simultaneously extends, by means of the notched lever, the front bellows portion and compresses the rear bellows portion to load the dosage cavity with medicament. Once the notched lever has extended the front bellows portion a predetermined distance, the notched lever is disengaged from the front bellows portion by the wedge-shaped arm extending from the rear wall of the housing, thereby releasing the front and rear bellows portions, along with the internal piston mechanism, to return to original position and force the medicament from the dosage cavity via a nozzle of the vial-dispenser.
