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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
Binding of sulfamethazine to β-cyclodextrin and methyl-β-cyclodextrin
Ariana Zoppi1, Alicia Delrivo, Virginia Aiassa
1Departamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina.
AAPS Pharmscitech
|April 23, 2013
Summary
This study prepared and characterized complexes of sulfamethazine (SMT) with cyclodextrins (βCD and MβCD), enhancing drug solubility. The resulting amorphous complexes show potential for pharmaceutical applications.
Area of Science:
- Pharmaceutical Chemistry
- Supramolecular Chemistry
- Drug Delivery
Background:
- Sulfamethazine (SMT) is an important sulfonamide antibiotic.
- Improving the solubility and bioavailability of poorly soluble drugs like SMT is crucial for effective drug delivery.
- Cyclodextrins, particularly β-cyclodextrin (βCD) and methyl-β-cyclodextrin (MβCD), are widely used to enhance drug solubility.
Purpose of the Study:
- To prepare and characterize complexes of sulfamethazine (SMT) with β-cyclodextrin (βCD) and methyl-β-cyclodextrin (MβCD).
- To evaluate the impact of βCD and MβCD on the aqueous solubility of SMT.
- To elucidate the complexation mechanism and characterize the solid-state properties of the SMT-cyclodextrin complexes.
Main Methods:
- Phase-solubility analysis was employed to assess the effect of βCD and MβCD on SMT solubility.
- (1)H NMR and 2D NMR spectroscopy were used to determine the complexation mode.
- Solid-state characterization involved Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermal analysis (DSC/TGA).
Main Results:
- Phase-solubility diagrams indicated increased water solubility of SMT in the presence of both βCD and MβCD.
- High affinity constants were calculated for SMT-βCD and SMT-MβCD complexes across different pH values.
- NMR studies revealed that the aromatic ring of SMT is included within the MβCD cavity, suggesting a specific inclusion complex formation.
- Characterization of freeze-dried complexes confirmed their amorphous nature, which is often beneficial for drug formulation.
Conclusions:
- Complexation with βCD and MβCD significantly enhances the aqueous solubility of sulfamethazine.
- The inclusion of SMT's aromatic ring into the MβCD cavity drives the complexation process.
- The amorphous nature of the prepared SMT-cyclodextrin complexes suggests their utility in developing improved pharmaceutical dosage forms for SMT.
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