title: Single step bottom-up process to generate solid phospholipid nano-particles.
abstract: BACKGROUND
  The particularity of the Nano Spray Dryer B-90 is the nozzle containing a mesh vibrating at ultrasonic frequency.
  
  
  OBJECTIVE
  To study process parameters and processability of crude phospholipid dispersions, in particular the effect of concentration and mesh aperture on both particle size of the dry solid phospholipid nano-particles and on the re-dispersed powder.
  
  
  METHODS
  Phospholipid dispersions containing trehalose as a stabilizer were spray dried. Particle size distributions of dry powders were evaluated by SEM micrographs and by PCS and cryo-TEM for the re-dispersed particles.
  
  
  RESULTS
  Spray drying of crude liposome dispersions revealed solid phospholipid nano-particles. Aperture of nozzle mesh and concentration of the dispersions, respectively, both increased the size of solid phospholipid nano-particles. For crude dispersions, an upper limit with respect to processability was found close to below 10% (m/m) even if the crude dispersion was passed along the mesh several times; however, more effective dispersing methods such as pre-sonication can push the limit of processability to higher values.
  
  
  CONCLUSIONS
  The nano spray dryer is capable of spray drying crude dispersions of phospholipids in concentrations below 10% (m/m) generating solid phospholipid nano-particles relevant for pulmonary delivery. Re-dispersion of spray dried powder reveals liposomes.
authors.affiliation: Institute of Physics, Chemistry and Pharmacy, University of Southern Denmark , Odense M , Denmark and.
authors.forename: Ulla
authors.initials: U
authors.lastname: Brinkmann-Trettenes
authors.forename: Sabine
authors.initials: S
authors.lastname: Barnert
authors.forename: Annette
authors.initials: A
authors.lastname: Bauer-Brandl
mesh_terms: D003890:Desiccation; D004337:Drug Carriers / Q000737:chemistry*; D005079:Excipients / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D010743:Phospholipids / Q000737:chemistry*; D011208:Powders; D013678:Technology, Pharmaceutical
chemical_list: D004337:Drug Carriers; D005079:Excipients; D008081:Liposomes; D010743:Phospholipids; D011208:Powders