An inhaler article includes a body extending along a longitudinal axis from a mouthpiece end to a distal end with an endpiece element at the distal end. A capsule cavity is defined within the body and extends along the longitudinal axis a cavity length. The capsule cavity includes a helical feature on or in an inner surface of the capsule cavity. The helical feature extends along the cavity length. An air inlet region is between the endpiece element and the capsule cavity. The air inlet region has an air inlet and an air passageway extending from the air inlet to the capsule cavity. A porous element defines a downstream end of the capsule cavity. A mouthpiece air channel extends from the capsule cavity, through the porous element to the mouthpiece end.