Drug delivery device

Abstract

A kit includes a drug delivery device and a dispensing unit. The drug delivery device includes a housing, a resetting element and a piston rod and the dispensing unit includes a cartridge holder. The cartridge holder is configured to be mounted to the housing and to receive a cartridge filled with a drug. The piston rod is configured to move in a proximal direction out of the housing to eject the drug and the resetting element is configured to rotate relative to the housing when no dispensing unit is attached to the housing and to thereby move the piston rod back into the housing. The dispensing unit is configured to press axially against the resetting element upon mounting to the housing to move the resetting element in the distal direction into the housing, and thereby rotationally lock the resetting element with respect to the housing.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims priority to European Patent Application No. 21167293.6 filed on Apr. 7, 2021, European Patent Application No. 21181883.6 filed on Jun. 25, 2021, European Patent Application No. 21181887.7 filed on Jun. 25, 2021, and European Patent Application No. 21184545.8 filed on Jul. 8, 2021, the contents of each of which are hereby incorporated herein by reference in their entirety.BACKGROUNDField of the Invention[0002]The invention relates to a drug delivery device comprising a housing, a cartridge holder, a resetting element and a piston rod.Background Information[0003]To date, conventional drug delivery devices which can be used by medically non-trained people, such as for example patients, to self-administer medicaments are becoming more and more sophisticated in view of their dose setting mechanisms and / or their dose delivery mechanisms. Uses of such devices can include, for example, diabetics, where medication management...

AI Technical Summary

Benefits of technology

The patent text describes a resetting element that can be rotated to fully reset a piston rod in a housing. This ensures that the piston rod can be completely moved back to its original position, regardless of whether it has been previously used. The text also mentions that a cartridge holder can be used to securely hold a cartridge in place, reducing the risk of damage during mounting. Additionally, the cartridge holder and cartridge can be sold as a single item, improving marketing efficiency.

Problems solved by technology

Although such a mechanism provides a particularly simple approach for the user to reset the device, it has been found that such mechanisms often lead to an inaccurate resetting of the piston rod and / or to accelerated wear of the device.

It has also been found that resetting the device by directly pushing the piston rod can be especially cumbersome if the piston rod is connected to a dosing mechanism of the device via a threaded connection that forces the piston rod to rotate upon movement along the longitudinal axis of the device.

Potential damage to the device is then especially likely to occur if the thread is nearly self-locking so that the user has to apply a significant force to make the piston rod rotate and therefore translate back into the housing.

By pushing the piston rod back into the housing, it can then happen that too great a force is applied to the rod, thereby pushing the rod axially over its thread.

As a consequence, its thread can wear out rather easily.

Additionally, it cannot be ensured that the piston rod is always completely returned such that an accurate dose setting is provided.

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