DESCRIPTION (Applicant's abstract): Asthma is one of the most common and costly illnesses in the United States, and drug formulation delivered via metered inhalers (MDIs) represent the primary treatment method for asthma sufferers. A key current issue in this arena is that the chlorofluorocarbon (CFC) propellants traditionally used in MDIs are being phased out by the government due to their high ozone-depletion potential--thus presenting a need for a replacement that is safe, effective, and economical. Although hydrofluoroalkane (HFA) propellants were thought to be a good candidate, potential problems include toxicity, incompatibility with devices, incompatibility with FDA-approved inhaler surfactants, and reduced bioavailability of some drugs. During Phase I Aerophase clearly demonstrated the feasibility of using CO2 as the next-generation propellant for pulmonary aerosol delivery of pharmaceuticals. Advantages include zero ozone-depletion potential, low toxicity, and the ability to administer to the lungs lipophilic drugs that cannot currently be delivered by any other method. A novel, high performance MicroBurst MDI design was tested successfully. The Phase II project proposed here would allow Aerophase to optimize candidate CO2-based formulations (e.g. albuterol, beclomethasone dipropionate, and budesonide) and to complete the design, development, and validation of the one or more MDIs in preparation for FDA approval and ultimate commercialization. PROPOSED COMMERCIAL APPLICATION: Beyond the initial goal of producing CO2-based drug formulations and MDIs for the effective treatment of asthma, the system we are pursuing could also be used effectively to deliver antibiotics to reduce death from pneumonia, possibly replace the need to inject insulin, deliver drugs that cannot be administered by any other method, provide targeted lung cancer therapy, and deliver rapid intervention against chemical warfare agents.