The present invention relates to inhalation formulations of drugs in the form of dry powder for inhalation administration deliverable as such with an inhaler and provided with high deliverability, respirability and stability. In particular, the invention relates to a pharmaceutical composition for inhalation in the form of powder comprising at least a first and a second powder, in which at least said first powder contains an active agent in an amount greater than 1% by weight with respect to the weight of said first powder. Both the powders comprise leucine in an amount ranging from 5 to 70% by weight with respect to the weight of each powder and a sugar in an amount ranging from 20 to 90% by weight with respect to the weight of each powder. The composition has a fine particle fraction (FPF) greater than 60% and a delivered fraction (DF) greater than 80.