Administering an injection is a process which presents a number of risks and challenges for users and healthcare professionals, both mental and physical.
Injection devices typically fall into two categories—manual devices and autoinjectors. In a conventional manual device, a user must provide force to drive a medicament through a needle. This is typically done by some form of button/plunger that has to be continuously pressed during the injection. There are numerous disadvantages for the user from this approach. For example, if the user stops pressing the button/plunger, the injection will stop and may not deliver an intended dose to a patient. Further, the force required to push the button/plunger may be too high for the user (e.g., if the user is elderly). And, aligning the injection device, administering the injection and keeping the injection device still during the injection may require dexterity which some patients (e.g., elderly patients, children, arthritic patients, etc.) may not have.
Autoinjector devices aim to make self-injection easier for patients. A conventional autoinjector may provide the force for administering the injection by a spring, and trigger button or other mechanism may be used to activate the injection. Autoinjectors may be single-use or reusable devices. Autoinjectors may be single-dose, delivering the entire contents of a cartridge or pre-filled syringe, or may be fixed-dose, delivering predetermined amounts from the cartridge or pre-filled syringe.
There remains a need for an improved, fixed-dose autoinjector.