Various embodiments of a valved holding chamber and a mask for a respiratory drug delivery apparatus each having an exhalation valve element having two portions which, based on the movement thereof, encourages proper use of the device. Also, a valved holding chamber having an MDI adapter having a rigid outer portion and a flexible inner portion structured to receive and hold an outlet of an MDI. In addition, a mouthpiece assembly for a valved holding chamber that includes a main body portion and a mouthpiece portion having a plurality of legs for supporting the valved holding chamber in a first orientation and preventing it from freely rolling.
