The present invention relates to methods for producing nanoparticle and microparticle powders of a biologically active material which have improved powder handling properties making the powders suitable for commercial use using dry milling processes as well as compositions comprising such materials, medicaments produced using said biologically active materials in particulate form and/or compositions, and to methods of treatment of an animal, including man, using a therapeutically effective amount of said biologically active materials administered by way of said medicaments.