Physicochemical Characterization of Veronicafolin‐β‐cyclodextrin and Solubility Enhancement of Veronicafolin‐HP‐β‐cyclodextrin Inclusion Compound

Abstract Inclusion complexation between veronicafolin, 3,5,4′‐trihydroxy‐6,7,3′‐trimethoxyflavone, and β‐cyclodextrin (β‐CD) was investigated by using1H NMR, IR, X‐ray diffraction, thermo gravimetric analysis (TGA), and elemental analysis in the solid state. The elemental analysis showed that the complex (1:1) of flavonol‐β‐CD·20H2O with C 39.58% and H 5.75% has been formed. The phase solubility profile of the favonol by UV‐Vis in solution in the presence of hydroxypfropyl‐β‐cyclodextrin (HP‐β‐CD) was classified as AL‐type, indicating the formation of 1:1 inclusion complex. And the calibration equationy=24148x+0.0075 (r=0.9999) and phase‐solubility diagram y=0.4738x‐2.0×10‐7(r=0.9490) were obtained. Stability constant Kswas calculated from the phase solubility diagram (Ks=4.5×106). Solubility of the veronicafolin was enhanced in the presence of HP‐β‐CD.