title: A pragmatic test of a simple calorimetric method for determining the fragility of some amorphous pharmaceutical materials.
abstract: OBJECTIVE
  To evaluate a simple calorimetric method for estimating the fragility of amorphous pharmaceutical materials from the width of the glass transition region.
  
  
  METHODS
  The glass transition temperature regions of eleven amorphous pharmaceutical materials were characterized at six different heating and cooling rates by differential scanning calorimetry (DSC).
  
  
  RESULTS
  Activation energies for structural relaxation (which are directly related to glass fragility) were estimated from the scan rate dependence of the glass transition temperature, and correlations between the glass transition widths and the activation energies were examined. The expected correlations were observed, and the exact nature of the relationship varied according to the type of material under consideration.
  
  
  CONCLUSIONS
  The proposed method of determining the fragility of amorphous materials from the results of simple DSC experiments has some utility, although "calibration" of the method for each type of materials is necessary. Further work is required to establish the nature of the relationships for a broad range of amorphous pharmaceutical materials.
authors.affiliation: Merck Frosst Canada Inc., Kirkland, Quebec, Canada. bruno_hancock@merck.com
authors.forename: B C
authors.initials: BC
authors.lastname: Hancock
authors.forename: C R
authors.initials: CR
authors.lastname: Dalton
authors.forename: M J
authors.initials: MJ
authors.lastname: Pikal
authors.forename: S L
authors.initials: SL
authors.lastname: Shamblin
mesh_terms: D002151:Calorimetry; D004735:Energy Transfer; D008433:Mathematics; D004364:Pharmaceutical Preparations / Q000737:chemistry*
chemical_list: D004364:Pharmaceutical Preparations