Artemether/hydroxypropyl-beta-cyclodextrin host-guest system: characterization, phase-solubility and inclusion mode.

An inclusion complex of the antimalarial artemether (ATM) in hydroxypropyl-beta-cyclodextrin (HPbetaCD) was prepared and characterized. The phase-solubility diagram for the drug showed an increase in water solubility and gave an apparent binding constant of 220 M(-1). According to (1)H NMR and 2D NMR spectroscopy (ROESY), the inclusion mode involves two CH(3) from the drug orientated in the HPbetaCD cavity. The complex was characterized by Powder X-ray diffraction and thermal analysis. In addition, the complex produces a 1.81-fold enhancement in apparent bioavailability compared to artemether.