title: Binding of sulfamethazine to β-cyclodextrin and methyl-β-cyclodextrin.
abstract: β-cyclodextrin (βCD) and methyl-β-cyclodextrin (MβCD) complexes with sulfamethazine (SMT) were prepared and characterized by different experimental techniques, and the effects of βCD and MβCD on drug solubility were assessed via phase-solubility analysis. The phase-solubility diagram for the drug showed an increase in water solubility, with the following affinity constants calculated: 40.4±0.4 (pH 2.0) and 29.4±0.4 (pH 8.0) M(-1) with βCD and 56±1 (water), 39±3 (pH 2.0) and 39±5 (pH 8.0) M(-1) with MβCD. According to (1)H NMR and 2D NMR spectroscopy, the complexation mode involved the aromatic ring of SMT included in the MβCD cavity. The complexes obtained in solid state by freeze drying were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and thermal analysis. The amorphous complexes obtained in this study may be useful in the preparation of pharmaceutical dosage forms of SMT.
authors.affiliation: Departamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina.
authors.forename: Ariana
authors.initials: A
authors.lastname: Zoppi
authors.forename: Alicia
authors.initials: A
authors.lastname: Delrivo
authors.forename: Virginia
authors.initials: V
authors.lastname: Aiassa
authors.forename: Marcela Raquel
authors.initials: MR
authors.lastname: Longhi
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002626:Chemistry, Pharmaceutical; D003890:Desiccation; D004337:Drug Carriers; D005615:Freezing; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008855:Microscopy, Electron, Scanning; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013418:Sulfamethazine / Q000737:chemistry*; D013678:Technology, Pharmaceutical / Q000379:methods; D013818:Thermogravimetry; D014867:Water / Q000737:chemistry; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D000890:Anti-Infective Agents; D004337:Drug Carriers; D012997:Solvents; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D014867:Water; D013418:Sulfamethazine