Medication delivery apparatus and system and methods for the use and assembly thereof

A medication delivery system comprising:

• a chamber housing having an exit port;
• a patient interface coupled to the chamber housing in fluid communication with the exit port, wherein the patient interface defines an inhalation conduit and comprises a user interface exit port spaced apart from the chamber housing exit port in a longitudinal direction, the patient interface comprising a viewing port area disposed above the inhalation conduit, wherein the viewing port is in fluid communication with the inhalation conduit through a first opening, wherein the viewing port area comprises a forwardly facing portion integrally formed with the patient interface, and a rearwardly facing portion coupled to the forwardly facing portion, wherein the forwardly and rearwardly facing portions define an interior space of the viewing port area, wherein the forwardly facing portion is positioned closer to the user interface exit port than the rearwardly facing portion, and wherein the rearwardly facing portion has a second opening in fluid communication with the ambient environment, wherein the second opening is spaced from the first opening;
• and
• a flow control member disposed in the interior space of the viewing port area, wherein the movement of the flow control member in response to inhalation creates a seal that prevents entrainment of ambient air through the second opening.