Propellant-Driven Aerosols of Proteins

Abstract

ABSTRACT The protein bovine gammaglobulin was combined with surfactants, suspended in dimethylether propellant, and delivered through metered-dose aerosol valves to produce small particle aerosols of protein. A fraction of the protein particles was of respirable size (≤ 4 μm aerodynamic diameter) as determined by cyclone or impactor aerosol sampling. Protein/surfactant molar rations of 1:1000 to 2000 produced the greatest percentage of respirable-sized protein particles. Excessive surfactant reduced the fraction of respirable-sized particles, whereas too little surfactant limited the suspension of protein in liquified propellant. Low protein/ surfactant densities in propellant increased the fraction of respirable-sized protein particles in aerosols, with 28%-36% of aerosolized protein of respirable size when protein concentrations were 0.2 mg/ml of propellant. Protein densities of up to 4 mg/ml in propellant could be delivered as aerosols, but with a reduced respirable fraction. Aqueous solutions of prote...