A disposable syringe assembly for use in an autoinjector device, or manually includes a syringe housing which receives the syringe barrel and which is restrained against longitudinal movement with respect thereto, a shield portion mounted for generally telescopic movement relative to the syringe housing between a retracted position and an extended position in which in use it shields the syringe needle, and a lock out arrangement activated as the shield moves towards its extended position to prevent retraction therefrom. When fitted in an autoinjector the autoinjector may include drive mechanism for moving the shield portion to its locked out extended position, whereby, on completion of an injection operation, the disposable syringe assembly may be removed from the autoinjector in a shielded condition for subsequent disposal.
