COMPOSITION COMPRISING AT LEAST ONE DRY POWDER OBTAINED BY SPRAY DRYING TO INCREASE THE STABILITY OF THE FORMULATION

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 use in powder form comprising a first powder comprising at least a powder (a1) comprising an active agent or a pharmaceutically acceptable salt thereof, in an amount greater than 1% by weight of the powder, leucine in an amount from 5 to 70% by weight of said powder, a sugar in an amount from 20 to 90% by weight of the powder; and a second powder comprising a mixture of a first lactose which has an X50 from 35 to 75 ?m, with a second lactose which has an X50 from 1.5 to 10 ?m, the content of the first and second lactose in the mixture are respectively from 85% to 96% and from 4% to 15%. The ratio by weight between the first powder and the second powder is from 1/5 to 1/100, and the composition has a fine particle fraction (FPF) greater than 60% and a delivered fraction (DF) greater than 85%.