| 摘要 |
The disclosure relates to pressurised metered dose inhalers (MDIs) for the effective administration of pharmaceutical aerosol formulations. The inhaler has an aerosol container containing an aerosol formulation, with the canister in communication via a metered expansion valve with an elongated expansion chamber, the chamber having an emission orifice disposed at a position between 65% and 75% along the length of the elongated expansion chamber in a direction away from the metered valve. Such formulations comprise a drug, a propellant comprising one of either 1,1,1,2-tetrafluoroethane (HFA134a) or 1,1,1,2,3,3,3-heptafluoropropane (HFA227) or a mixture thereof, a co-solvent having a higher polarity than HFA134a or HFA227, and a surfactant in an amount at least 0.01 % by weight of said formulation. Such MDIs comprise a canister. The propellant has a pressure between 70 and 85 psi.
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