title: Formulation of inhalable lipid-based salbutamol sulfate microparticles by spray drying technique.
abstract: BACKGROUND
  The aim of this work was to develop dry powder inhaler (DPI) formulations of salbutamol sulfate (SS) by the aid of solid lipid microparticles (SLmPs), composed of biocompatible phospholipids or cholesterol.
  
  
  METHODS
  The SLmPs were prepared by using two different solvent systems (ethanol and water-ethanol) and lipid carriers (dipalmitoylphosphatidylcholine (DPPC) and cholesterol) with/without L-leucine in the spray drying process. The spray-dried microparticles were physically-mixed with coarse lactose monohydrate in order to make our final DPI formulations and were investigated in terms of physical characteristics as well as in vitro drug release profile and aerosolization behavior.
  
  
  RESULTS
  We observed significant differences in the sizes, morphologies, and in vitro pulmonary depositions between the formulations. In particular, the SS-containing SLmPs prepared with water-ethanol (30:70 v/v) solution of DPPC and L-leucine which had then been blended with coarse lactose (1:9 w/w) exhibited the highest emitted dose (87.9%) and fine particle fraction (42.7%) among the formulations. In vitro drug release study indicated that despite of having a significant initial burst release for both cholesterol and DPPC-based microparticles, the remained drug released more slowly than the pure drug.
  
  
  CONCLUSIONS
  This study demonstrated the potential of using lipid carriers as well as L-leucine in DPI formulations of SS to improve its aerosolization behavior and retard the release profile of the drug.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Daman
authors.affiliation: Aerosol Research Laboratory, Department of Pharmaceutics, School of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran. gilani@tums.ac.ir.
authors.forename: Kambiz
authors.initials: K
authors.lastname: Gilani
authors.forename: Abdolhossein
authors.initials: A
authors.lastname: Rouholamini Najafabadi
authors.forename: Hamid Reza
authors.initials: HR
authors.lastname: Eftekhari
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Barghi
mesh_terms: D000280:Administration, Inhalation; D000420:Albuterol / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics*; D001993:Bronchodilator Agents / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics*; D002626:Chemistry, Pharmaceutical; D003890:Desiccation / Q000379:methods; D058995:Dry Powder Inhalers; D008081:Liposomes; D008855:Microscopy, Electron, Scanning; D010316:Particle Size
chemical_list: D001993:Bronchodilator Agents; D008081:Liposomes; D000420:Albuterol