Stabilized dispersions are provided for the delivery of a bioactive agent to the respiratory tract of a patient. The dispersions preferably comprise a plurality of perforated microstructures dispersed in a suspension medium that typically comprises a hydrofluoroalkane propellant. As density variations...http://www.google.de/patents/US20010046474?utm_source=gb-gplus-sharePatent US20010046474 - Stabilized preparations for use in metered dose inhalers
