The present disclosure provides a method of preparing a pharmaceutical composition. The method includes transferring a predetermined quantity of an excipient mixture from a second vessel to a first vessel. The excipient mixture transferred from the second vessel includes a liquid-state second quantity of a hydrofluoroalkane propellant and a first solubilized excipient comprising a low-molecular weight poly(ethylene oxide) polymer. The method further includes contacting at least one pharmaceutically-active compound with the excipient mixture under conditions that facilitate forming an intermixture comprising the propellant, the polymer, and the compound. Before transferring the excipient mixture, the first vessel contains a vapor-phase first quantity of the hydrofluoroalkane propellant and an effective amount of the at least one pharmaceutically-active compound.
