A system comprising: a cartridge holder having a cartridge holder distal end , a cartridge holder proximal end , a sidewall extending therebetween defining a chamber having an interior adapted to receive a cartridge therein, and a recessed portion on the interior surface of the sidewall ; a stopper slidably disposed within an interior of the cartridge ; and a latch member removably secured or locked to the cartridge holder , the latch member comprising a rocker pivotally mounted to a portion of the latch member , the rocker comprising an upper arm engageable with a portion of the cartridge holder and a lower arm comprising a portion configured to engage a portion of a plunger rod , characterized in that the plunger rod is engageable with a portion of the stopper and is adapted to communicate with the latch member , the plunger rod comprising a protrusion , the latch member is secured or locked to the cartridge holder by rotating the latch member relative to the cartridge holder , which moves the upper arm into the recessed portion , and movement of the plunger rod in a distal direction through the latch member causes the plunger rod to transition between: a disengaged position, in which the protrusion of the plunger rod is disengaged from the portion of the lower arm of the latch member and the latch member is locked to the cartridge holder ; and an engaged position, in which the rocker pivots to allow the protrusion to slide past portion of the lower arm of the latch member , such that the latch member is unlocked from the cartridge holder and the portion of the lower arm locks to the protrusion of the plunger rod . a cartridge holder having a cartridge holder distal end , a cartridge holder proximal end , a sidewall extending therebetween defining a chamber having an interior adapted to receive a cartridge therein, and a recessed portion on the interior surface of the sidewall ; a stopper slidably disposed within an interior of the cartridge ; and a latch member removably secured or locked to the cartridge holder , the latch member comprising a rocker pivotally mounted to a portion of the latch member , the rocker comprising an upper arm engageable with a portion of the cartridge holder and a lower arm comprising a portion configured to engage a portion of a plunger rod , characterized in that the plunger rod is engageable with a portion of the stopper and is adapted to communicate with the latch member , the plunger rod comprising a protrusion , the latch member is secured or locked to the cartridge holder by rotating the latch member relative to the cartridge holder , which moves the upper arm into the recessed portion , and movement of the plunger rod in a distal direction through the latch member causes the plunger rod to transition between: a disengaged position, in which the protrusion of the plunger rod is disengaged from the portion of the lower arm of the latch member and the latch member is locked to the cartridge holder ; and an engaged position, in which the rocker pivots to allow the protrusion to slide past portion of the lower arm of the latch member , such that the latch member is unlocked from the cartridge holder and the portion of the lower arm locks to the protrusion of the plunger rod . <EOS>