title: Preparation and Evaluation of Multiple Nanoemulsions Containing Gadolinium (III) Chelate as a Potential Magnetic Resonance Imaging (MRI) Contrast Agent.
abstract: OBJECTIVE
  The objective was to develop, characterize and assess the potentiality of W1/O/W2 self-emulsifying multiple nanoemulsions to enhance signal/noise ratio for Magnetic Resonance Imaging (MRI).
  
  
  METHODS
  For this purpose, a new formulation, was designed for encapsulation efficiency and stability. Various methods were used to characterize encapsulation efficiency ,in particular calorimetric methods (Differential Scanning Calorimetry (DSC), thermogravimetry analysis) and ultrafiltration. MRI in vitro relaxivities were assessed on loaded DTPA-Gd multiple nanoemulsions.
  
  
  RESULTS
  Characterization of the formulation, in particular of encapsulation efficiency was a challenge due to interactions found with ultrafiltration method. Thanks to the specifically developed DSC protocol, we were able to confirm the formation of multiple nanoemulsions, differentiate loaded from unloaded nanoemulsions and measure the encapsulation efficiency which was found to be quite high with a 68% of drug loaded. Relaxivity studies showed that the self-emulsifying W/O/W nanoemulsions were positive contrast agents, exhibiting higher relaxivities than those of the DTPA-Gd solution taken as a reference.
  
  
  CONCLUSIONS
  New self-emulsifying multiple nanoemulsions that were able to load satisfactory amounts of contrasting agent were successfully developed as potential MRI contrasting agents. A specific DSC protocol was needed to be developed to characterize these complex systems as it would be useful to develop these self-formation formulations.
authors: U1022 INSERM, UMR8258 CNRS, Unité de Technologies Chimiques et Biologiques pour la Santé, Chimie ParisTech, Faculty of Pharmacy, Paris Descartes University, Sorbone Paris Cité, 75006, Paris, France.
authors: Estelle
authors: E
authors: Sigward
authors: Yohann
authors: Y
authors: Corvis
authors: Bich-Thuy
authors: BT
authors: Doan
authors: Kadri
authors: K
authors: Kindsiko
authors: Johanne
authors: J
authors: Seguin
authors: Daniel
authors: D
authors: Scherman
authors: Denis
authors: D
authors: Brossard
authors: Nathalie
authors: N
authors: Mignet
authors: Philippe
authors: P
authors: Espeau
authors: Sylvie
authors: S
authors: Crauste-Manciet
mesh_terms: D002614:Chelating Agents / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical / Q000379:methods; D003287:Contrast Media / Q000737:chemistry*; D004655:Emulsions / Q000737:chemistry*; D005682:Gadolinium / Q000737:chemistry*; D019786:Gadolinium DTPA / Q000737:chemistry*; D008279:Magnetic Resonance Imaging / Q000379:methods; D053758:Nanoparticles / Q000737:chemistry*
chemical_list: D002614:Chelating Agents; D003287:Contrast Media; D004655:Emulsions; D005682:Gadolinium; D019786:Gadolinium DTPA