title: Physicochemical characterization of 2-hydroxybenzophenone with β-cyclodextrin in solution and solid state.
abstract: The characterization of the inclusion complex between 2-hydroxybenzophenone (2OHBP) and β-cyclodextrin (βCD) in the solid state was performed using Fourier transform infrared spectroscopy (FTIR), powder X-ray diffractometry (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM). The apparent formation constant of the complex was determined by phase solubility diagrams and liquid chromatography (HPLC) at different temperatures. The formation of the inclusion complex induced slight shifts in the FTIR spectrum while by PXRD a new crystalline phase was observed. TEM studies revealed that the complex forms aggregates of nanometric size. The inclusion complex showed a higher solubility in the tested dissolution media than free 2OHBP. Moreover, the freeze-dried solid complex exhibits a higher thermal stability than the solid free drug. The thermodynamic analysis allowed us to conclude that the encapsulation process is endothermic in water and exothermic in methanol-water.
authors.forename: Matias I
authors.initials: MI
authors.lastname: Sancho
authors.forename: Marcos G
authors.initials: MG
authors.lastname: Russo
authors.affiliation: §Instituto Balseiro, Centro Atómico Bariloche, San Carlos de Bariloche 8400, Argentina.
authors.forename: M Sergio
authors.initials: MS
authors.lastname: Moreno
authors.forename: Estela
authors.initials: E
authors.lastname: Gasull
authors.forename: Sonia E
authors.initials: SE
authors.lastname: Blanco
authors.forename: Griselda E
authors.initials: GE
authors.lastname: Narda
mesh_terms: D001577:Benzophenones / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002851:Chromatography, High Pressure Liquid; D019277:Entropy; D006860:Hydrogen Bonding; D000432:Methanol / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D015394:Molecular Structure; D012995:Solubility; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D001577:Benzophenones; D012996:Solutions; D047392:beta-Cyclodextrins; D014867:Water; C031215:betadex; C562127:ortho-hydroxybenzophenone; D000432:Methanol