title: Studies on the effect of the size of polycaprolactone microspheres for the dispersion of salbutamol sulfate from dry powder inhaler formulations.
abstract: OBJECTIVE
  To study the effect of the size of the surface-coated polycaprolactone (PCL) microparticle carriers on the aerosolization and dispersion of Salbutamol Sulfate (SS) from Dry Powder Inhaler (DPI) formulations.
  
  
  METHODS
  The microparticles were fabricated using an emulsion technique in four different sizes (25, 48, 104 and 150 μm) and later coated with Magnesium stearate (MgSt) and leucine. They were characterized by laser diffraction and SEM. The Fine Particle Fraction (FPF) of SS from powder mixtures was determined by a Twin Stage Impinger (TSI).
  
  
  RESULTS
  As the carrier size increased from 25 μm to 150 μm, the FPF of the SS delivered by the coated PCL particles increased approximately four fold. A linear relationship was found between the FPF and Volume mean Diameter (VMD) of the particles over this range.
  
  
  CONCLUSIONS
  The dispersion behaviour of SS from PCL carriers was dependent on the inherent size of the carriers and the increased FPF of SS with increased carrier size probably reflects the higher mechanical forces produced due to the carrier-carrier collisions or collisions between the carrier particles and the internal walls of the inhaler during aerosolization.
authors.affiliation: Institute of Health and Biomedical Innovation, 60 Musk Avenue, Kelvin Grove, QLD 4059, Australia.
authors.forename: Rinku A
authors.initials: RA
authors.lastname: Tuli
authors.forename: Graeme A
authors.initials: GA
authors.lastname: George
authors.forename: Tim R
authors.initials: TR
authors.lastname: Dargaville
authors.forename: Nazrul
authors.initials: N
authors.lastname: Islam
mesh_terms: D000420:Albuterol / Q000008:administration & dosage*; D001993:Bronchodilator Agents / Q000737:chemistry*; D004337:Drug Carriers; D058995:Dry Powder Inhalers; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010316:Particle Size; D011091:Polyesters / Q000008:administration & dosage / Q000737:chemistry*
chemical_list: D001993:Bronchodilator Agents; D004337:Drug Carriers; D011091:Polyesters; C016240:polycaprolactone; D000420:Albuterol