title: Inhalable nanocomposite microparticles: preparation, characterization and factors affecting formulation.
abstract: BACKGROUND
  Nanocomposite microparticles are intelligent carriers utilised for pulmonary drug delivery. These carriers are composed of drug-encapsulated nanoparticles dispersed in microstructures of polysaccharides. Upon administration, the inhaled microparticles can penetrate and be deposited deeply in the lung due to their adjusted aerodynamic particle size. Subsequently, the nanoparticles are released into the lung and are retained there for a prolonged time due to their resistance to immunological opsonisation, engulfment and digestion.
  
  
  METHODS
  Nanocomposite microparticles may be prepared by spray drying, spray freeze drying, spray drying fluidised bed granulation or dry coating techniques. The selection of the included excipients, preparation technique and optimisation of the operational parameter play a significant role in the determination of the aerodynamic particle size, redispersibility of the nanoparticles, morphology, yield, moisture content, flowability and in vitro drug release. Moreover, the in vivo behaviour of this novel carrier may be optimised and traced by studying the lung deposition of the inhaled particles and the biological activity of the encapsulated drug.
  
  
  CONCLUSIONS
  Nanocomposite microparticles have been found to be superior to both nanoparticles and microparticles and may represent a promising carrier for pulmonary drug delivery.
authors.affiliation: a Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy , Cairo University , Cairo 11562 , Egypt Tel: +20 1149944306 ; Fax: +20 233058256 ;|b College of Pharmacy , Gulf Medical University , Ajman , UAE.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Elsayed
authors.affiliation: a Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy , Cairo University , Cairo 11562 , Egypt Tel: +20 1149944306 ; Fax: +20 233058256 ;|c Department of Industrial and Physical Pharmacy, College of Pharmacy , Purdue University , West Lafayette , IN , USA.
authors.forename: Mohamed Hassan Hany
authors.initials: MH
authors.lastname: AbouGhaly
mesh_terms: D000280:Administration, Inhalation; D016503:Drug Delivery Systems / Q000379:methods*; D064420:Drug-Related Side Effects and Adverse Reactions; D005079:Excipients / Q000737:chemistry; D005612:Freeze Drying; D053761:Nanocomposites / Q000737:chemistry*; D010316:Particle Size; D013678:Technology, Pharmaceutical / Q000379:methods*
chemical_list: D005079:Excipients
keywords: aerodynamic particle size; lung deposition; nanocomposite microparticles; spray drying