title: Direct formation of nanospheres from amphiphilic beta-cyclodextrin inclusion complexes.
abstract: OBJECTIVE
  The aim of this work was to develop and characterize a highly loaded nanoparticulate system based on amphiphilic beta-cyclodextrins (CDs) to facilitate the parenteral administration of poorly soluble antifungal model drugs bifonazole and clotrimazole.
  
  
  METHODS
  Inclusion complexes were characterized with spectroscopic techniques. Particle size distribution of nanospheres were determined by photon correlation spectroscopy (PCS). Nanospheres were assessed for hemolytic activity. Entrapped and released drug quantities were determined and minimum inhibitory concentration (MIC) values of drugs, amphiphilic beta-CDs, and drug loaded nanospheres were evaluated.
  
  
  RESULTS
  1:1 inclusion complexes of model drugs with amphiphilic beta-CDs gave nanospheres <300 nm (polydispersity index < 0.15) by nanoprecipitation technique without using surfactants. By direct preparation from preformed inclusion complexes, loading was increased 2- to 8-fold depending on CD type and loading technique. Conventionally loaded CD nanospheres displayed immediate release whereas preloaded and highly loaded nanospheres liberated model drugs over a period of 1 h reducing the initial burst effect. MIC values of bifonazole and clotrimazole were lowered significantly when associated to amphiphilic beta-CD nanospheres.
  
  
  CONCLUSIONS
  Amphiphilic beta-CDs form nonsurfactant, highly loaded nanospheres with lower hemolytic activity than that of natural CDs directly from inclusion complexes. They enhanced solubility and subsequently therapeutic efficacy of the model drugs.
authors.affiliation: Hacettepe University, Faculty of Pharmacy, Department of Pharmaceutical Technology, 06100 Ankara, Turkey.
authors.forename: Erem
authors.initials: E
authors.lastname: Memişoğlu
authors.forename: Amélie
authors.initials: A
authors.lastname: Bochot
authors.forename: Meral
authors.initials: M
authors.lastname: Ozalp
authors.forename: Murat
authors.initials: M
authors.lastname: Sen
authors.forename: Dominique
authors.initials: D
authors.lastname: Duchêne
authors.forename: A Atilla
authors.initials: AA
authors.lastname: Hincal
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000493:pharmacokinetics; D002626:Chemistry, Pharmaceutical; D003505:Cyclodextrins / Q000737:chemistry* / Q000493:pharmacokinetics; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000706:statistics & numerical data; D008863:Microspheres; D036103:Nanotechnology / Q000379:methods*; D018709:Statistics, Nonparametric; D013501:Surface-Active Agents / Q000737:chemistry* / Q000493:pharmacokinetics; D047392:beta-Cyclodextrins
chemical_list: D000935:Antifungal Agents; D003505:Cyclodextrins; D013501:Surface-Active Agents; D047392:beta-Cyclodextrins; C031215:betadex