According to the subject invention, dispersible dry powder pharmaceutical-based compositions are provided, including methods for their manufacture and dry powder dispersion devices. A dispersible dry powder pharmaceutical-based composition is one having a moisture content of less than about 10% by weight (% w) water, usually below about 5% w and preferably less than about 3% w; a particle size of about 1.0-5.0 .mu.m mass median diameter (MMD), usually 1.0-4.0 .mu.m MMD, and preferably 1.0-3.0 .mu.m MMD; a delivered dose of about >30%, usually >40%, preferably >50%, and most preferred >60%; and an aerosol particle size distribution of about 1.0-5.0 .mu.m mass median aerodynamic diameter (MMAD), usually 1.5-4.5 .mu.m MMAD, and preferably 1.5-4.0 MMAD. Such composition are of pharmaceutical grade purity.