Drug/cyclodextrin: beyond inclusion complexation

Curcumin-Hydroxypropyl-β-Cyclodextrin Inclusion Complex Preparation Methods: Effect of Common Solvent Evaporation, Freeze Drying, and pH Shift on Solubility and Stability of Curcumin

“…The concentration of curcumin increased with increasing CD concentration. The relationships were linear and the slopes of the plots were between 0 and 1 indicating an A L -type of phase solubility according to Higuchi and Connors concepts [13,14]. These results indicate 1:1 curcumin-CD complex formation in all types of CDs studied.…”

“…The studies were carried out in triplicate. The relationships between CD concentrations (x-axis) and curcumin concentrations (y-axis) were plotted and the complexation constants were calculated according to the method described by Higuchi and Connors [13,14].…”

The effect of cyclodextrin mixtures on aqueous solubility of beclomethasone dipropionate

“…One or more CD molecules contain one or more entrapped molecules. Most frequently the host (CD):guest (drug) ratio is 1:1, 1:2 and 2:1 [6,7].…”

“…In A-type profiles, the apparent solubility of the substrate increases as a function of CD concentration but B-type profiles are indicative of the formation of complexes with limited water solubility [7,8]. The ability of a CD to form an inclusion complex with a guest molecule depends on the relative size of the CD to the size of the guest molecule or certain functional groups within the guest [4,5].…”

“…Recently, it has shown that CD and drug interaction is not limited to the inclusion complexation. Non-inclusion interactions exist in aqueous CD solution [7,10,11].…”