Host-guest interaction study of resveratrol with natural and modified cyclodextrins

The aim of this work is to increase the stability and water soly. of resveratrol by complexation with different cyclodextrins. Furthermore, phys.-chem. properties of each inclusion compd. were investigated. Complexes of resveratrol with cyclodextrins both native (a, b, g) and modified (2-hydroxypropyl-b-cyclodextrin, dimethyl-b-cyclodextrin) were obtained by using the suspension method. An inclusion complex with b-cyclodextrin was also prepd. by using the microwave. Solid state characterization of the products was carried out using Fourier transform IR spectroscopy (FT-IR), differential scanning calorimetry (DSC), x-ray diffraction (DRX); soln. studies were performed by UV-Vis spectrophotometry and 1H-NMR spectroscopy. Phase soly. profiles with all cyclodextrins employed were classified as AN type, indicating the formation of 1:1 stoichiometric inclusion complexes. Stability consts. (Kc) from the phase soly. diagrams were calcd. Stability studies in the solid state and in soln. were performed; the photodegrdn. by UV-Vis spectrophotometry was monitored. The isomerization rate trans to cis, in ethanol soln., decreased with inclusion. The dissoln. studies revealed that resveratrol dissoln. rate was improved by the formation of inclusion complexes