title: Processing of spherical crystalline particles via a novel solution atomization and crystallization by sonication (SAXS) technique.
abstract: OBJECTIVE
  The objective was to develop a single-step pharmaceutical particle engineering technique able to produce particles within a well-defined particle size range while controlling macroscopic spherical morphology and mesoscopic surface topography.
  
  
  METHODS
  Paracetamol (acetaminophen) aerosol droplets were generated by spraying a solution via either an electrohydrodynamic atomizer (EHDA) or an air pressure atomizer. The highly supersaturated droplets were collected in a suitable nonsolvent of the drug and crystallized by ultrasonication. Suspended particles were filtered, and their physicochemical properties characterized.
  
  
  RESULTS
  The SAXS processed particles showed a relatively homogeneous particle size distribution between 1 and 5 microm. Particles were nominally crystalline in structure. The chemical structure of the active ingredient did not apparently alter during processing. Controlling the solute concentration of the air pressure atomized solution provided a means of controlling the degree of sphericity and particle-size characteristics. In comparison to micronized paracetamol particles, SAXS-produced particulates were generally more uniform in shape with increased nanometer surface roughness.
  
  
  CONCLUSIONS
  The SAXS process provides a novel means of producing crystalline particles in a well-defined particle size range. Furthermore, the method offers a range of opportunities in controlling physical properties including surface topography and particle shape.
authors.affiliation: Pharmaceutical Technology Research Group, Department of Pharmacy and Pharmacology, University of Bath, Bath BA2 7AY, UK.
authors.forename: J Sebastian
authors.initials: JS
authors.lastname: Kaerger
authors.forename: Robert
authors.initials: R
authors.lastname: Price
mesh_terms: D000082:Acetaminophen / Q000737:chemistry; D000336:Aerosols / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003460:Crystallization; D018625:Microscopy, Atomic Force; D008854:Microscopy, Electron; D008863:Microspheres; D009330:Nebulizers and Vaporizers; D010316:Particle Size; D013010:Sonication / Q000295:instrumentation*; D013499:Surface Properties; D014961:X-Ray Diffraction
chemical_list: D000336:Aerosols; D000082:Acetaminophen