Abstract: An autoinjector includes a main body having a container, the container having a drug therein, a hollow needle coupled to the container through which the drug can be delivered. The autoinjector also has a power source having a liquefied gas therein as a driver, a flow regulator, and at least one outlet through which some of the driver can exit the power pack in a gaseous state. The power source and container are coupled together for operation such that, when an injection is initiated, the flow regulator will control an exit rate of the driver such that the liquefied gas in the power source is maintained at substantially its vapor pressure and the power source will adjustably apply a force to deliver the drug via the hollow needle at a delivery rate that is a constant delivery rate.

Abstract: A power pack, for use in an autoinjector to deliver a drug from a container at an injection rate includes a power pack body configured to hold a liquefied gas and a flow regulator, the power pack body further including at least one outlet through which some of the liquefied gas can exit the power pack in a gaseous state such that, during use, the flow regulator will control a rate of exit flow such that the liquefied gas in the canister is maintained at substantially its vapor pressure, while the gas leaving the outlet applies an adaptively changing force to the drug in the container so that delivery of the drug will occur at about a constant injection rate.

Abstract: An autoinjector includes a main body having a container, the container having a drug therein, a hollow needle coupled to the container through which the drug can be delivered. The autoinjector also has a power source having a liquefied gas therein as a driver, a flow regulator, and at least one outlet through which some of the driver can exit the power pack in a gaseous state. The power source and container are coupled together for operation such that, when an injection is initiated, the flow regulator will control an exit rate of the driver such that the liquefied gas in the power source is maintained at substantially its vapor pressure and the power source will adjustably apply a force to deliver the drug via the hollow needle at a delivery rate that is a constant delivery rate.