Novel inclusion complex of ibuprofen tromethamine with cyclodextrins: physico-chemical characterization.

Guest-host interactions of ibuprofen tromethamine salt (Ibu.T) with native and modified cyclodextrins (CyDs) have been investigated using several techniques, namely phase solubility diagrams (PSDs), proton nuclear magnetic resonance ((1)H NMR), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffractometry (XRPD), scanning-electron microscopy (SEM) and molecular mechanics (MM). From the analysis of PSD data (A(L)-type) it is concluded that the anionic tromethamine salt of ibuprofen (pK(a)=4.

Fexofenadine/cyclodextrin inclusion complexation: phase solubility, thermodynamic, physicochemical, and computational analysis.

Interactions of fexofenadine (Fexo) with cyclodextrins (CDs: alpha- beta-, gamma-, and HP-beta-CD) were investigated by several techniques including phase solubility, differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD), (1)H-nuclear magnetic resonance ((1)H-NMR) and molecular mechanical modeling (MM(+)). The effects of CD type, pH, ionic strength, and temperature on complex stability were also explored. Fexo/CD complex formation follows the decreasing order: beta-CD > HP-beta-CD > gamma-CD > alpha-CD (i.

Changes in the conformational structure, microscopic and macroscopic pK(a)s of meloxicam on complexation with natural and modified cyclodextrins.

Spectroscopic and phase solubility techniques have been used to study the complexation of neutral meloxicam (Mel) with alpha-, beta-, gamma- and HP-beta-cyclodextrins (CDs). The results indicate that neutral Mel has two conformational structures, enol and zwitterions, with the latter more dominant in water. The two pK(a)s of Mel were found to change in the presence of beta-CD, where a blue shift in lambdamax was observed but not in the presence of alpha, HP-beta- and gamma-CD.

Sildenafil/cyclodextrin complexation: stability constants, thermodynamics, and guest-host interactions probed by 1H NMR and molecular modeling studies.

Guest-host interactions of sildenafil (Sild) with cyclodextrins (CyDs) have been investigated using several techniques including phase solubility diagrams (PSD), differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD), proton nuclear magnetic resonance (1H NMR) and molecular mechanical modeling (MM+). Estimates of the complex formation constant (K11) show that the tendency of Sild to complex with CyDs follows the order: beta-CyD>HP-beta-CyD>gamma-CyD, alpha-CyD, where K11 values at pH 8.7 and 30 degrees C were 150, 68 and 46, 43 M-1, respectively.

Thermodynamics of propylparaben/beta-cyclodextrin inclusion complexes.

The aim of this study was to develop models for rigorous analysis of phase solubility diagrams, particularly the descending portion, in order to obtain individual thermodynamic complex formation and solubility product constants. Additionally, the effect of varying the initial solute concentration St, in excess of the optimal solubility Sm, on the general shape of the plateau and descending portions of the solubility diagram was investigated. The solubilities of propylpapraben (Seq) were measured against initial beta-cyclodextrin concentrations (Lt) at different temperatures and different St.