Pharmaceutical compositions for inhalation as dry powders, solutions or suspensions

Pharmaceutical composition dry solid for inhalation comprising a drug, a soluble carrier having a solubility in water greater than 5 g / l and a surfactant, wherein: - said soluble excipient comprises leucine is present in an amount between 10% and less than 100% by weight; - the weight ratio between said surfactant and said drug is between 0.01 and 10; - the particle size of at least 50% of the particles (X50) of said powder is less than 5 .mu.m; - the bulk density db of said powder is between 0.1 and 0.3 g / cm3; - density dt of said powder is settlement of between 0.15 and 0.7 g / cm3; - the ratio db / dt is between 0.2 and 0.65; wherein said excipient and said surfactant phospholipids include not.