WET-DRY RECONSTITUTING INJECTION PEN

摘要

An injection pen for use with a dual chamber cartridge having a chamber and partition system with a plurality of operational states, including at least a reconstitution state, a primed state and an injected state. The injection pen includes a tubular housing, a plunger, and a state control system comprising one or more detents and a plurality of stops. The plunger is slidably supported within the tubular housing so that the drive rod of the plunger abuts one end of the chamber and partition system and forces the dual chamber cartridge to change operational states as the drive rod moves axially through the housing in response to an external force applied to the opposite end of the plunger. The detent and plurality of stops in the state control system temporarily suspend the axial travel of the plunger as the dual chamber cartridge enters each new operational state.