Aerosolization of Chelating Agent, Ca-DTPA, for Emergent Inhalation Therapy.

Aerosolization of the chelating agent, Ca-DTPA (diethylenetriaminepentaacetic acid), was studied for removal of inhaled radioactive particles. Four methods of generating aerosols from the powder and from the solution were examined. The particle size and concentration of the Ca-DTPA aerosols were measured by the API Aero-Sizer. The aerosol particles generated by the dry powder inhaler were over 40μm in MMAD (Mass Median Aerodynamic Diameter) and might be too large for administration to the deep lung. The sizes of aerosol particles generated by other three methods (dispersion dust generator, compressed air nebulizer and ultrasonic nebulizer) ranged from 2 to 15μm in MMAD, and those concentrations were over 10mg/m3 at maximum. The generated chelate aerosols were evaluated as inhalable and applicable for inhalation therapy.