Dry powder compositions for intranasal delivery

A pharmaceutical composition in a form of dry powder for intranasal administration includes solid particles of at least one active agent and solid particles of a diluent. The pharmaceutical composition is substantially free of excipients other than the solid diluent. The pharmaceutical composition has at least 90% of the particles of the at least one active agent with a mean particle size of 10-30 microns and less than 10% of the particles of the at least one active agent with a mean particle size equal to or below 5 microns. The particles of the diluent have a mean particle size of 30-200 microns. An apparatus and method for preparation of the pharmaceutical composition utilize a spray-drying chamber, a cyclone separator, and a receiving chamber.