A powder formulation for use by inhalation in the prevention and/or treatment of an inflammatory and/or obstructive airways disease, said powder comprising: a carrier, comprising: (a) 80 to 95 percent by weight, based on the total weight of said carrier, of coarse particles of alpha-lactose monohydrate having a mean particle size of at least 175 μm and a mass diameter comprised between 100 and 600 micron; and (b) 19.6 to 4.9 percent by weight, based on the total weight of said carrier, of micronized particles of alpha-lactose monohydrate, and 0.1 to 0.4 percent by weight, based on the total weight of said carrier, of magnesium stearate; and micronized particles of glycopyrronium bromide, beclometasone dipropionate, and formoterol fumarate dihydrate, as active ingredients, wherein said formulation is obtainable by a process comprising: i) mixing all of said coarse particles of alpha-lactose monohydrate, all of said magnesium stearate, a first portion of said micronized particles of a physiologically acceptable excipient, all of said micronized particles of glycopyrronium bromide, beclometasone dipropionate, and formoterol fumarate dihydrate in a vessel of a shaker mixer at a speed of rotation not lower than 16 rpm for a time of not less than 60 minutes, to obtain a first mixture; and (ii) adding the remaining part of said micronized particles of a physiologically acceptable excipient to said first mixture, to obtain a second mixture, and mixing said second mixture at a speed of rotation not lower than 16 rpm for a time of at least 120 minutes; wherein said first portion of said micronized particles of alpha-lactose monohydrate is comprised between 40% and 60%, based on the total weight of all of said micronized particles of alpha-lactose monohydrate; and wherein the extrafine particle fraction of each active ingredient is comprised between 20 and 35%. a carrier, comprising: (a) 80 to 95 percent by weight, based on the total weight of said carrier, of coarse particles of alpha-lactose monohydrate having a mean particle size of at least 175 μm and a mass diameter comprised between 100 and 600 micron; and (b) 19.6 to 4.9 percent by weight, based on the total weight of said carrier, of micronized particles of alpha-lactose monohydrate, and 0.1 to 0.4 percent by weight, based on the total weight of said carrier, of magnesium stearate; and (a) 80 to 95 percent by weight, based on the total weight of said carrier, of coarse particles of alpha-lactose monohydrate having a mean particle size of at least 175 μm and a mass diameter comprised between 100 and 600 micron; and (b) 19.6 to 4.9 percent by weight, based on the total weight of said carrier, of micronized particles of alpha-lactose monohydrate, and 0.1 to 0.4 percent by weight, based on the total weight of said carrier, of magnesium stearate; and micronized particles of glycopyrronium bromide, beclometasone dipropionate, and formoterol fumarate dihydrate, as active ingredients, wherein said formulation is obtainable by a process comprising: i) mixing all of said coarse particles of alpha-lactose monohydrate, all of said magnesium stearate, a first portion of said micronized particles of a physiologically acceptable excipient, all of said micronized particles of glycopyrronium bromide, beclometasone dipropionate, and formoterol fumarate dihydrate in a vessel of a shaker mixer at a speed of rotation not lower than 16 rpm for a time of not less than 60 minutes, to obtain a first mixture; and (ii) adding the remaining part of said micronized particles of a physiologically acceptable excipient to said first mixture, to obtain a second mixture, and mixing said second mixture at a speed of rotation not lower than 16 rpm for a time of at least 120 minutes; wherein said first portion of said micronized particles of alpha-lactose monohydrate is comprised between 40% and 60%, based on the total weight of all of said micronized particles of alpha-lactose monohydrate; and wherein the extrafine particle fraction of each active ingredient is comprised between 20 and 35%. i) mixing all of said coarse particles of alpha-lactose monohydrate, all of said magnesium stearate, a first portion of said micronized particles of a physiologically acceptable excipient, all of said micronized particles of glycopyrronium bromide, beclometasone dipropionate, and formoterol fumarate dihydrate in a vessel of a shaker mixer at a speed of rotation not lower than 16 rpm for a time of not less than 60 minutes, to obtain a first mixture; and (ii) adding the remaining part of said micronized particles of a physiologically acceptable excipient to said first mixture, to obtain a second mixture, and mixing said second mixture at a speed of rotation not lower than 16 rpm for a time of at least 120 minutes;