A unit dose dry powder inhaler , comprising: an inhaler base defining a capsule seat that is configured to hold a capsule containing a powdered medicament, the inhaler base comprising at least one primary air intake that is in fluid communication with the capsule seat , wherein the at least one primary air intake is configured to, in use, draw air into the capsule seat so as to generate rapid capsule precession and centrifugal forces that fluidize and disperse powder agglomerates; a grid positioned between the inhaler base and a mouthpiece, wherein the inhaler is structured such that, in use, entrained powder is drawn through the grid resulting in dispersion of powder agglomerates via impaction forces with the static grid; an inlet funnel positioned between the grid and a dispersion chamber , wherein the inlet funnel tapers to a small inlet orifice into the dispersion chamber resulting, in use, in dispersion of powder agglomerates via shear forces generated at the orifice ; the dispersion chamber , that is adapted to entrain powder from the inlet funnel , the dispersion chamber holding an actuator that is configured to oscillate within the dispersion chamber during inhalation resulting in dispersion of powder agglomerates by dynamic impaction with the actuator and increased turbulence within the dispersion chamber ; and the mouthpiece , that includes an outlet funnel through which air and aerosolized medicament exit the inhaler to be delivered to a patient, wherein the outlet funnel is tapered to, in use, reduce or minimize particle velocity and turbulence at an exit of the mouthpiece to the patient, characterised in that : the grid has a diameter of between 10 mm and 20 mm; the diameter of the inlet funnel at its grid side matches the diameter of the grid; and a diameter of the orifice is between 2.8 mm and 3.4 mm. an inhaler base defining a capsule seat that is configured to hold a capsule containing a powdered medicament, the inhaler base comprising at least one primary air intake that is in fluid communication with the capsule seat , wherein the at least one primary air intake is configured to, in use, draw air into the capsule seat so as to generate rapid capsule precession and centrifugal forces that fluidize and disperse powder agglomerates; a grid positioned between the inhaler base and a mouthpiece, wherein the inhaler is structured such that, in use, entrained powder is drawn through the grid resulting in dispersion of powder agglomerates via impaction forces with the static grid; an inlet funnel positioned between the grid and a dispersion chamber , wherein the inlet funnel tapers to a small inlet orifice into the dispersion chamber resulting, in use, in dispersion of powder agglomerates via shear forces generated at the orifice ; the dispersion chamber , that is adapted to entrain powder from the inlet funnel , the dispersion chamber holding an actuator that is configured to oscillate within the dispersion chamber during inhalation resulting in dispersion of powder agglomerates by dynamic impaction with the actuator and increased turbulence within the dispersion chamber ; and the mouthpiece , that includes an outlet funnel through which air and aerosolized medicament exit the inhaler to be delivered to a patient, wherein the outlet funnel is tapered to, in use, reduce or minimize particle velocity and turbulence at an exit of the mouthpiece to the patient, characterised in that : the grid has a diameter of between 10 mm and 20 mm; the diameter of the inlet funnel at its grid side matches the diameter of the grid; and a diameter of the orifice is between 2.8 mm and 3.4 mm. the grid has a diameter of between 10 mm and 20 mm; the diameter of the inlet funnel at its grid side matches the diameter of the grid; and a diameter of the orifice is between 2.8 mm and 3.4 mm. <EOS>