title: A novel gas phase method for the combined synthesis and coating of pharmaceutical particles.
abstract: OBJECTIVE
  A novel aerosol flow reactor method for the combined gas phase synthesis and coating of particles for drug delivery has been developed.
  
  
  METHODS
  As an example, micron-sized salbutamol sulfate particles were produced via droplet-to-particle conversion and in-situ coated by the physical vapor deposition (PVD) of L-leucine vapor.
  
  
  RESULTS
  During the deposition, L-leucine vapor crystallized on the surfaces of amorphous salbutamol particles. The size of L-leucine crystallites increased with increasing vapor concentration of L-leucine. The salbutamol particles with rough L-leucine surfaces exhibited good flowability enabling to them to be dispersed into air flow without the delivery aid of coarse lactose carriers.
  
  
  CONCLUSIONS
  The fraction of particles smaller than 5 micrometers varied between 0.35 and 0.48 when dispersed into 60 l/min air flow having a jet Reynolds number of 30700. When the coated fine particles were blended with lactose carriers, the fine particle fraction was as high as 90%. The L-leucine coating also improved the stability of salbutamol particles when stored at 45% relative humidity atmosphere.
authors.affiliation: NanoMaterials Group, Laboratory of Physics & Center for New Materials, Helsinki University of Technology, Espoo, Finland.
authors.forename: Janne
authors.initials: J
authors.lastname: Raula
authors.forename: Anna
authors.initials: A
authors.lastname: Lähde
authors.forename: Esko I
authors.initials: EI
authors.lastname: Kauppinen
mesh_terms: D000336:Aerosols; D000420:Albuterol / Q000008:administration & dosage / Q000737:chemistry; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000737:chemistry; D004339:Drug Compounding; D005740:Gases; D007930:Leucine / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size
chemical_list: D000336:Aerosols; D001993:Bronchodilator Agents; D005740:Gases; D007930:Leucine; D000420:Albuterol