Stabilized preparations for use in metered dose inhalers

A system for the pulmonary administration of a bioactive agent comprising:

• a fluid reservoir;
• a metering valve operably associated with said fluid reservoir;
• and
• a stabilized dispersion in said fluid reservoir wherein said stabilized dispersion comprises a suspension medium having dispersed therein a plurality of perforated microstructures comprising at least one bioactive agent wherein. said suspension medium comprises at least one propellant and substantially permeates said perforated microstructures.

A method for the pulmonary delivery of one or more bioactive agents comprising the steps of:

• providing a pressurized reservoir containing a stabilized respiratory dispersion comprising a suspension medium having dispersed therein a plurality of perforated microstructures comprising one or more bioactive agents, wherein said suspension medium comprises a propellant and substantially permeates said perforated microstructures;
• aerosolizing said respiratory dispersion by releasing pressure on the pressurized reservoir to provide an aerosolized medicament comprising said perforated microstructures;
• and
• administering a therapeutically effective amount of said aerosolized medicament to at least a portion of the pulmonary passages of a patient in need thereof.

A method of increasing the effective pulmonary deposition of a bioactive agent using a metered dose inhaler comprising the steps of:

• associating said bioactive agent with a plurality of perforated microstructures having a mean aerodynamic diameter of less than about 5 μm;
• dispersing said perforated microstructures in a suspension medium comprising a propellant to provide a respiratory dispersion;
• and
• charging a metered dose inhaler with said respiratory dispersion wherein said charged metered dose inhaler provides a fine particle fraction of greater than approximately 20% w/w upon activation.