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Transport Properties of Ibuprofen Encapsulated in Cyclodextrin Nanosponge Hydrogels: A Proton HR-MAS NMR Spectroscopy Study
Published on: August 15, 2016
Complexation of sulfonamides with beta-cyclodextrin studied by experimental and theoretical methods
Ariana Zoppi1, Mario A Quevedo, Alicia Delrivo
1Departamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina.
Journal of Pharmaceutical Sciences
|February 19, 2010
Summary
This study investigated the complex formation between sulfonamides (sulfadiazine, sulfamerazine, sulfamethazine) and beta-cyclodextrin. Hydrophobicity drives complex formation, with varying affinities and inclusion modes observed for each sulfonamide.
Area of Science:
- Supramolecular Chemistry
- Pharmaceutical Sciences
Background:
- Sulfonamides are a class of antibiotics with varying structures.
- Beta-cyclodextrin (beta-CD) is a cyclic oligosaccharide known for its ability to form inclusion complexes.
Purpose of the Study:
- To investigate the complex formation between three sulfonamides (sulfadiazine, sulfamerazine, sulfamethazine) and beta-cyclodextrin.
- To explore the structure-affinity relationship in these inclusion complexes.
Main Methods:
- Phase solubility studies to determine stoichiometry and relative affinities.
- Nuclear Magnetic Resonance (NMR) spectroscopy to elucidate spatial configurations.
- Molecular modeling to predict and confirm complex structures.
- Energetic analyses to identify driving forces for complexation.
Main Results:
- 1:1 stoichiometry was observed for all sulfonamide-beta-CD complexes.
- Phase solubility indicated affinity order: sulfadiazine > sulfamerazine > sulfamethazine.
- NMR and molecular modeling revealed distinct inclusion modes: sulfadiazine included its aniline ring, while sulfamerazine and sulfamethazine included the substituted pyrimidine ring.
- Energetic analysis identified hydrophobicity as the primary driving force for complex formation.
Conclusions:
- The study elucidates the complexation behavior of sulfonamides with beta-cyclodextrin.
- Structural differences among sulfonamides dictate their inclusion mode and affinity for beta-CD.
- Hydrophobic interactions are crucial for the stability of these supramolecular complexes.
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