A pharmacological powder for inhalation comprising fine particles of a drug and particles of a force-controlling agent, wherein the particles of said force-controlling agent are disposed on the surface of the active particles as either a particulate coating, or as a continuous or discontinuous film. The powder may further comprise particles of a carrier material for supporting the drug particles. The force-controlling agent may be selected from: amino acids, peptides and polypeptides having a molecular weight of from 0.25 to 1000 KDa； phospholipids； titanium dioxide； aluminium dioxide； silicon dioxide； starch； and salts of fatty acids. Also disclosed is a method of making such a powder for inhalation comprising mixing a force-controlling agent with particles of one or more pharmacologically active materials to obtain a mixture in which the particles of said force-controlling agent are disposed on the surface of the active particles as either a particulate coating, or as a continuous or discontinuous film. The mixing step may be achieved by sieving, mixing or blending, micronising and/or co-micronising the particles of one or more pharmacologically active material and particles of force-controlling agents.
