A method and system are disclosed for driving a plunger in a drug reservoir. In some embodiments, a variable friction element interconnects between a pushing shaft and a wall of the reservoir. For example, rotation of a driving element in a first direction relative to the pushing shaft may advance the pushing shaft in the reservoir. The friction element may have increased friction resistance to rotation of the pushing shaft in the first direction in comparison to frictional resistance to advancing the pushing shaft. For example, the increased friction may result from wedging a radial element between the pushing shaft and the wall of the reservoir.

A drive assembly for a medication delivery device is provided which is switchable from an operational state to a resetting state and which comprises: a housing having a proximal end and a distal end, a drive member adapted to be rotated with respect to the housing, and a stop member adapted to prevent rotational movement of the drive member in a first direction with respect to the housing and to permit rotational movement of the drive member in a second direction with respect to the housing, the second direction being opposite to the first direction. In the operational state of the drive assembly the stop member is held in engagement with the drive member, and for switching into the resetting state of the drive assembly the stop member is enabled to disengage from the drive member caused by gravity due to the weight of the stop member. Moreover, in the operational state of the drive assembly the drive member may be held in engagement with a rotation member, and for switching into the resetting state of the drive assembly the drive member may be enabled to disengage from the rotation member caused by gravity due to the weight of the drive member.

In an embodiment, an injection simulation device is provided including a housing defining a channel, the housing comprising a proximal end and a distal end, a plunger comprising a plunger rod body having a proximal end and a distal end and a stopper disposed at the distal end of the plunger rod, the plunger movable proximally and distally within the channel; and a friction feature associated with the housing, the friction feature for interfacing with the plunger rod, wherein the plunger moves in a distal direction relative to the housing to simulate medicament delivery and in a proximal direction to reset the injection simulation device, wherein the friction feature optionally causes differential resistance on the plunger rod, when the plunger rod moves in either the distal or proximal direction.

The present invention relates a botulinum toxin prefilled syringe system with desirable injection force characteristics, in particular low gliding force and low break loose force, comprising a syringe barrel of glass containing a liquid botulinum toxin composition, a plunger stopper and a closure device such as a tip cap or a needle shield. In addition, the present invention relates to a kit comprising the botulinum toxin prefilled syringe system, and optionally instructions for use, and to the use of the botulinum toxin prefilled syringe system in therapeutic and cosmetic applications.

An Injection device (10) comprises an injection solution receptacle (30) and a plunger (70) at least a portion of which is slidably received in the injection solution receptacle (30), wherein the plunger (70) is displaceable relative to the injection solution receptacle (30) in a distal direction in order to expel an injection solution contained In the injection solution receptacle (30) from the injection solution receptacle (30). A first plunger stop mechanism (140) is adapted to stop a displacement of the plunger (70) relative to the injection solution receptacle (30) in the distal direction at a first dosing position (P1). A second plunger stop mechanism (140) is adapted to stop a displacement of the plunger (70) relative to the injection solution receptacle (30) from the first dosing position (P1) in the distal direction at a second dosing position (P2), wherein the first and the second dosing position (P2) of the plunger (70) are selected in such a manner that the plunger (70), upon being displaced relative to the Injection solution receptacle (30) between the first and the second dosing position (P2) Is adapted to expel a desired dose of the injection solution contained in the Injection solution receptacle (30) from the injection solution receptacle (30).

A needleless injector includes a housing part including an accommodating space that is configured to accommodate a substance intended for injection an actuator configured to generate an ejection energy and a plunger coupled to the housing part so as to define the accommodating space, including a weakened part and a distal end, and configured to receive the ejection energy from the actuator as a driving force. The plunger is further configured to move in the housing part by the driving force so that the distal end reaches to a deepest part of the housing part when the driving force is equal to or smaller than a predefined force, and deform at the weakened part by the driving force before the distal end reaches to the deepest part of the housing part when the driving force exceeds the predefined force.

The invention concerns improvements in needle-free devices for delivery of therapeutic and/or prophylactic agents, such as solid dose drugs, including vaccines. The needle-free device disclosed herein comprises novel structural arrangements and modes of actuation and operation, resulting in enhanced functionality and benefits to the user and/or patient.

A needleless injector includes a housing part including an accommodating space that is configured to accommodate a substance intended for injection an actuator configured to generate an ejection energy and a plunger coupled to the housing part so as to define the accommodating space, including a weakened part and a distal end, and configured to receive the ejection energy from the actuator as a driving force. The plunger is further configured to move in the housing part by the driving force so that the distal end reaches to a deepest part of the housing part when the driving force is equal to or smaller than a predefined force, and deform at the weakened part by the driving force before the distal end reaches to the deepest part of the housing part when the driving force exceeds the predefined force.