The present study wasconducted to investigate the inclusion complexation of artemisinin (ART) withnatural cyclodextrins (CyD), namely alpha-, beta-, and gamma-CyDs with the aimof improving its solubility and dissolution rate. Complex formation in aqueoussolution and solid state was studied by solubility analysis, dissolution, andthermal analysis. Solubility diagrams indicated that the complexation of ARTand the three CyDs occurred at a molar ratio of 1:1, and showed a remarkableincrease in ART solubility. Moreover, the thermodynamic parameters calculatedby using the van't Hoff equation revealed that the complexation process wasassociated with negative enthalpy of formation and occurred spontaneously. Thecomplexation capability of CyDs with ART increased in the order of alpha- <gamma- < beta-CyDs and could be ascribed to the structural compatibilitybetween the molecular size of ART and the diameter of the CyD cavities.Dissolution profiles of the three complexes demonstrated an increased rate andextent of dissolution compared with those of their respective physical mixturesand a commercial preparation. In solid-state analysis, using differentialscanning calorimetry, the gamma-CyD was capable of complexing the highestpercentage of ART, followed by beta- and alpha-CyDs. The respective estimatedpercentage of ART complexed by the CyDs were 85%, 40%, and 12%.