Inclusion Complexation of Artemisinin with α-, β-, and γ-Cyclodextrins

AbstractThe present study was conducted to investigate the inclusion complexation of artemisinin (ART) with natural cyclodextrins (CyD), namely α-, β-, and γ-CyDs with the aim of improving its solubility and dissolution rate. Complex formation in aqueous solution and solid state was studied by solubility analysis, dissolution, and thermal analysis. Solubility diagrams indicated that the complexation of ART and the three CyDs occurred at a molar ratio of 1:1, and showed a remarkable increase in ART solubility. Moreover, the thermodynamic parameters calculated by using the van’t Hoff equation revealed that the complexation process was associated with negative enthalpy of formation and occurred spontaneously. The complexation capability of CyDs with ART increased in the order of α- <γ- <β-CyDs and could be ascribed to the structural compatibility between the molecular size of ART and the diameter of the CyD cavities. Dissolution profiles of the three complexes demonstrated an increased rate and extent of dis...