Abstract: A medicament delivery device (100) for delivery of medicament through a cannula (132) from a cartridge (10), the device comprising a first container (11) for storage of a first substance, a second container (12), and valve means for closing a distal end of the second chamber (12), the second container (12) being arranged coaxially with respect to the first container (11), a mixing element (304) being provided for causing displacement of the second substance into the first container (11) through the valve means in a mixing stroke, a release element being provided for holding the mixing element (304) in an initial position and being operable to release the mixing element (304) to initiate the mixing stroke, there being a needle shroud (400) for shrouding the cannula, and removal of the needle shroud (400) from the cannula (132) causing operation of the release element.

Abstract: Syringes are described herein. A syringe includes a syringe body, a first plunger, a biasing member, and a priming indicator. The syringe body defines a syringe cavity, a syringe port, and an indicator window, wherein the syringe port is in fluid communication with the syringe cavity. The first plunger comprises a first plunger shaft extending from the first plunger, the first plunger disposed within the syringe cavity and defining a first chamber in the syringe cavity, wherein the first chamber is in fluid communication with the syringe port. The biasing member couples to the first plunger shaft, wherein the biasing member urges the first plunger from an unprimed position to a primed position toward the syringe port. The priming indicator presents the first indicator portion through the indicator window in the unprimed position and presents the second indicator portion through the indicator window in the primed position.

Abstract: A fixed dose injector pen is provided that includes a transmission element that is rotated to set and deliver a dose of a drug from a multi-dose cartridge. A circular ratchet defines a small number of engagement positions around its circumference and selectively transmits the rotation of the transmission element to a piston rod driver. The circular ratchet transmits the rotation of the transmission element to the piston rod driver only when the transmission element is rotated in a dose delivery direction, and only if the transmission element has previously been rotated in an opposite, dose setting direction through an angle sufficient to reach one of the engagement positions. An axially moving injector element can be used to drive rotation of the transmission element via a helical coupling. When the piston rod has advanced to a predetermined axial position, a last dose lock-out mechanism maintains the circular ratchet in engagement.