A dry powder inhaler includes a dose container assembly having a dose container disk with opposing upper and lower surfaces, a first row of circumferentially spaced apart dose containers at a first radius and a second row of circumferentially spaced apart dose containers at a second radius. The dose containers have dry powder therein and are sealed via a first flexible sealant over apertures in the upper surface and a second flexible sealant over apertures in the lower surface. A piercing mechanism includes two reciprocating piercers that serially alternate between the two rows of dose containers in the dose container disk. A rotatable ramp disk includes first and second sets of circumferentially spaced-apart ramp elements in staggered, concentric relationship that are configured to move the first and second piercing members between retracted and extended positions.