title: Nano spray-dried pyrazinamide-L-leucine dry powders, physical properties and feasibility used as dry powder aerosols.
abstract: OBJECTIVE
  The aim of this study was to investigate the effect of adding L-leucine and using an ethanolic solvent on the physicochemical properties and aerodynamic behavior of nano spray-dried pyrazinamide (PZA)-L-leucine powders.
  
  
  METHODS
  A nano spray dryer was employed to prepare PZA-L-leucine powders. The physicochemical properties were evaluated using a scanning electron microscope (SEM), differential scanning calorimetry and X-ray diffraction. The Andersen cascade impactor was used to evaluate the in vitro aerosolization performance of the sprayed powders.
  
  
  CONCLUSIONS
  The incorporation of L-leucine at 10% improved the percentage fine particle fraction (%FPF) in all ethanolic solvent formulations by up to nearly twofold (20.0-23.4%) compared to the normal spray-dried PZA of (8.8-13.0%). Changes in the particle density and morphology were also observed. The dense solid particles of PZA were completely converted to bulk hollow particles with a thin shell by increasing the L-leucine content up to 50%. Higher ethanol concentration resulted in larger dimensions of the hollow particle but did not directly affect the aerosolization performance. The co-spray dried PZA with 20% L-leucine in a 10% ethanol feed solvent gave the best aerosolization performance (FPF = 33.0%).
  
  
  CONCLUSIONS
  The co-spray dried PZA with a suitable L-leucine content using a nano spray drying technique could be applied to formulate the PZA DPI.
authors.affiliation: a Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences , Prince of Songkla University , Hat Yai , Songkhla , Thailand and.
authors.forename: Kanogwan
authors.initials: K
authors.lastname: Kaewjan
authors.affiliation: a Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences , Prince of Songkla University , Hat Yai , Songkhla , Thailand and.|b Faculty of Pharmaceutical Sciences, NANOTEC-PSU Excellence Center on Drug Delivery System , Prince of Songkla University , Hat Yai , Songkhla , Thailand.
authors.forename: Teerapol
authors.initials: T
authors.lastname: Srichana
mesh_terms: D000336:Aerosols / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D058995:Dry Powder Inhalers; D005240:Feasibility Studies; D007930:Leucine / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011208:Powders; D011718:Pyrazinamide / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D000336:Aerosols; D011208:Powders; D011718:Pyrazinamide; D007930:Leucine
keywords: Andersen cascade impactor; dry powder inhaler; lung delivery; nano spray dryer; tuberculosis