An injector comprising: a housing ; a frame being rotatably disposed within the housing ; a mixing assembly being disposed within the frame , the mixing assembly being configured to actuate in response to rotation of the frame with respect to the housing ; a trigger assembly; and a cap being disposed at a distal end of the housing over the trigger assembly, the cap being operatively connected to the housing on an interior portion, wherein rotation of the cap with respect to the housing imparts a relative rotation between the frame and the housing , thus actuating the mixing assembly , characterised in that the cap further comprises an interior channel being aligned axially, and wherein the frame further comprises an exterior protrusion corresponding in shape to the interior channel of the cap , wherein the interior channel and exterior protrusion are configured to allow an axial relative translation, but are constrained in a rotational degree of motion, and wherein the cap further comprises one or more protrusions , and wherein the housing further comprises a corresponding lip about a distal end, wherein the one or more protrusions of the cap engage the lip in a stowed and intermediate state, and wherein the protrusions disengage from the lip at a mixed state, wherein rotation of the cap relative to the housing causes the device to move from the stowed state, through the intermediate state, and into the mixed state, whereupon the cap is configured to release, and be removed from the housing , and wherein the rotation of the cap is limited between 35 to 90 degrees with respect to the housing and whereupon the cap is configured to be released from the housing after a rotation of 35 to 90 degrees. a housing ; a frame being rotatably disposed within the housing ; a mixing assembly being disposed within the frame , the mixing assembly being configured to actuate in response to rotation of the frame with respect to the housing ; a trigger assembly; and a cap being disposed at a distal end of the housing over the trigger assembly, the cap being operatively connected to the housing on an interior portion, wherein rotation of the cap with respect to the housing imparts a relative rotation between the frame and the housing , thus actuating the mixing assembly , characterised in that the cap further comprises an interior channel being aligned axially, and wherein the frame further comprises an exterior protrusion corresponding in shape to the interior channel of the cap , wherein the interior channel and exterior protrusion are configured to allow an axial relative translation, but are constrained in a rotational degree of motion, and wherein the cap further comprises one or more protrusions , and wherein the housing further comprises a corresponding lip about a distal end, wherein the one or more protrusions of the cap engage the lip in a stowed and intermediate state, and wherein the protrusions disengage from the lip at a mixed state, wherein rotation of the cap relative to the housing causes the device to move from the stowed state, through the intermediate state, and into the mixed state, whereupon the cap is configured to release, and be removed from the housing , and wherein the rotation of the cap is limited between 35 to 90 degrees with respect to the housing and whereupon the cap is configured to be released from the housing after a rotation of 35 to 90 degrees. <EOS>