title: Theoretical prediction of a phase diagram for solid dispersions.
abstract: OBJECTIVE
  To predict the temperature-composition phase diagram of solid dispersions (SDs) through theoretical approaches using cinnarizine-Soluplus(®) SD as a model system and evaluate the predicted results.
  
  
  METHODS
  A complete phase diagram of cinnarizine-Soluplus(®) SD, including the solubility curve, miscibility curve and glass transition temperature curve, was constructed on the basis of the solid-liquid equilibrium (SLE) equation, Florry-Huggins (F-H) theory and Fox equation. Cinnarizine-Soluplus(®) SDs with different drug loadings were prepared by hot melt extrusion. The extrudates and corresponding physical mixtures were analyzed to check the predicted results.
  
  
  RESULTS
  The experimental data revealed a solubility of 7.9 wt% at 110°C and a miscibility level of 65 wt% at room temperature, which were both consistent with predicted values.
  
  
  CONCLUSIONS
  The predicted phase diagram agrees well with the experimental results for the non-polar components which mainly interact through dispersion forces, thus facilitating the formulation design of SDs.
authors.affiliation: Department of Pharmaceutics Science, Shenyang Pharmaceutical University, Wenhua Road 103, Shenyang, 110016, Liaoning Province, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Tian
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Wang
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Keru
authors.initials: K
authors.lastname: Zhang
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xing
authors.initials: X
authors.lastname: Tang
mesh_terms: D002152:Calorimetry, Differential Scanning; D002626:Chemistry, Pharmaceutical; D002936:Cinnarizine / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D005079:Excipients / Q000737:chemistry*; D007700:Kinetics; D008853:Microscopy; D008956:Models, Chemical; D011092:Polyethylene Glycols / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D033362:Powder Diffraction; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013678:Technology, Pharmaceutical / Q000379:methods*; D044366:Transition Temperature
chemical_list: D005079:Excipients; D011145:Polyvinyls; C572167:polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer; D002936:Cinnarizine; D011092:Polyethylene Glycols