Abstract: A process for producing uniform small doses of finely divided substances that consists of metering precise quantities a material onto the surface of a containment vessel, pressurizing the containment vessel with a liquefied gas, and sealing the containment vessel while pressurized. A major application involves the packaging of fine pharmaceutical powders into small unit doses for inhalation therapy. Liquid nitrogen is a preferred liquefied pressurizing agent. A liquefied noble gas may be employed as a dispersing medium for sensitive or highly reactive substances, and simple hydrocarbon gasses may be used where flammability and reactivity are not problems. If the liquefied gas is used as a dispersing medium, the containment vessel may be sealed prior to the total evaporation of the liquid. Alternatively, the liquefied gas may be metered into the containment vessel after the substance has been deposited onto the surface of the containment vessel, but prior to its sealing.

Abstract: A process for producing uniform small doses of finely divided substances that consists of forming a well mixed dispersion of a finely divided substance in a liquefied gas and then metering precise quantities of the mixture onto the surface of a containment vessel. A major application involves the packaging of fine pharmaceutical powders into small unit doses for inhalation therapy. Liquid nitrogen is the preferred liquefied gas. A liquefied noble gas may be employed as a dispersing medium for sensitive or highly reactive substances. Powder particle size reduction may be carried out in the liquid nitrogen medium with little or no damage to sensitive pharmacological materials. The atmosphere of the seated containment vessel is easily pressurized with nitrogen. The containment vessel may be seated prior to the total evaporation of the liquefied gas dispersing medium.