title: Lactose composite carriers for respiratory delivery.
abstract: OBJECTIVE
  Lactose dry powder inhaler (DPI) carriers, constructed of smaller sub units (composite carriers), were evaluated to assess their potential for minimising drug-carrier adhesion, variability in drug-carrier forces and influence on drug aerosol performance from carrier-drug blends.
  
  
  METHODS
  Lactose carrier particles were prepared by fusing sub units of lactose (either 2, 6 or 10 microm) in saturated lactose slurry. The resultant composite particles, as well as supplied lactose, were sieve fractioned to obtain a 63-90 microm carriers. The carriers were evaluated in terms of size (laser diffraction) morphology (electron microscopy and atomic force microscopy), crystallinity and drug adhesion (colloid probe microscopy). In addition, blends containing drug and carrier were prepared and evaluated in terms of drug aerosol performance.
  
  
  RESULTS
  The surface morphology and physico-chemical properties of the composite carriers were significantly different. Depending on the initial primary lactose size, the composite particles could be prepared with different surface roughness. Variation in composite roughness could be related to the change in drug adhesion (via modification in contact geometry) and thus drug aerosol performance from drug-lactose blends.
  
  
  CONCLUSIONS
  Composite based carriers are a potential route to control drug-carrier adhesion forces and variability thus allowing more precise control of formulation performance.
authors.affiliation: Advanced Drug Delivery Group, Faculty of Pharmacy, University of Sydney, Sydney, NSW, 2006, Australia. py@pharm.usyd.edu.au
authors.forename: Paul M
authors.initials: PM
authors.lastname: Young
authors.forename: Philip
authors.initials: P
authors.lastname: Kwok
authors.forename: Handoko
authors.initials: H
authors.lastname: Adi
authors.forename: Hak-Kim
authors.initials: HK
authors.lastname: Chan
authors.forename: Daniela
authors.initials: D
authors.lastname: Traini
mesh_terms: D000268:Adhesiveness; D000280:Administration, Inhalation; D000336:Aerosols; D000420:Albuterol / Q000008:administration & dosage / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002626:Chemistry, Pharmaceutical; D003460:Crystallization; D018360:Crystallography, X-Ray; D004337:Drug Carriers; D004339:Drug Compounding; D007785:Lactose / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D009330:Nebulizers and Vaporizers; D010316:Particle Size; D033362:Powder Diffraction; D011208:Powders; D019141:Respiratory System Agents / Q000008:administration & dosage / Q000737:chemistry*; D013499:Surface Properties; D013678:Technology, Pharmaceutical / Q000379:methods
chemical_list: D000336:Aerosols; D004337:Drug Carriers; D011208:Powders; D019141:Respiratory System Agents; D007785:Lactose; D000420:Albuterol