title: Tetrafluoroethane (HFC 134A) propellant-driven aerosols of proteins.
abstract: OBJECTIVE
  Develop metered-dose propellant-driven aerosols of proteins using tetrafluoroethane (HFC 134A) as propellant.
  
  
  METHODS
  Proteins were lyophilized with the propellant-soluble surfactants Triton X-100, Triton X-405, Laureth-9, Brij-30, Nonidet-40, and diethylene glycol monoethylether and then charged with propellants.
  
  
  RESULTS
  Small particle aerosols of the experimental protein bovine gamma globulin were produced. The fraction of aerosolized respirable-sized protein particles (< 4-5 microns) increased after dispersion of particles in propellant with agitation by shaking. Scanning electron microscopy of respirable-sized protein aerosols demonstrated bead-like particles in grape-like clusters. Vigorous shaking of propellant-suspended particles for 2 minutes or more reduced the size of clusters and reduced the diameters of the protein-containing subparticles that constituted the clusters. A 50:50 ratio of HFC 134A and dimethylether (DME) propellants improved the respirability of protein aerosols compared to HFC 134A as the sole propellant. Protein/surfactant particles first dispersed in DME and then diluted in HFC 134A propellant most efficiently produced respirable-sized, propellant-driven, protein aerosols.
authors.affiliation: Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan 66506, USA. Brown@vet.ksu.edu
authors.forename: A R
authors.initials: AR
authors.lastname: Brown
authors.forename: D W
authors.initials: DW
authors.lastname: George
mesh_terms: D000335:Aerosol Propellants; D000336:Aerosols; D000818:Animals; D002417:Cattle; D003633:Dichlorodiphenyl Dichloroethylene / Q000008:administration & dosage / Q000031:analogs & derivatives; D004338:Drug Combinations; D016503:Drug Delivery Systems / Q000379:methods; D006845:Hydrocarbons, Fluorinated; D010316:Particle Size; D011506:Proteins / Q000008:administration & dosage*; D012995:Solubility; D013501:Surface-Active Agents / Q000008:administration & dosage; D005719:gamma-Globulins / Q000008:administration & dosage; D004980:Ethane / Q000031:analogs & derivatives; D005466:Fluorocarbons
chemical_list: D000335:Aerosol Propellants; D000336:Aerosols; D003633:Dichlorodiphenyl Dichloroethylene; D004338:Drug Combinations; D006845:Hydrocarbons, Fluorinated; D011506:Proteins; D013501:Surface-Active Agents; D005719:gamma-Globulins; C063006:norflurane; D004980:Ethane; D005466:Fluorocarbons