Pluronic F127-cyclodextrin conjugate micelles for encapsulation of honokiol

To overcome honokiol’s poor water solubility and investigate its antifungal activity and pharmacokinetic property, Pluronic® F-127 (F127)-cyclodextrin conjugate was synthesized and employed to prepare honokiol-loaded micelles through emulsion-solvent evaporation method. The drug-loaded micelles were obtained with 92.30 ± 3.28% of encapsulation efficiency being higher than that obtained from F127 due to additional cyclodextrin inclusion. Fourier transformation infrared spectrometry and diffraction scanning calorimetry analysis tests demonstrated that honokiol was successfully encapsulated into the conjugate micelles in the amorphous or solid solution state because of their interactions. Meanwhile, in vitro antifungal activity experiment indicated that the MIC90 of drug-loaded micelles was 64 μg/mL, showing the same antifungal activity as pure honokiol although it obviously retarded honokiol’s release. In vivo pharmacokinetic results confirmed that in vivo area under curve and apparent distribution volume of honokiol in drug-loaded micelles were 2- and 1.69-folds higher than that for pure honokiol, with its obvious prolonged mean retention time and half-life period, respectively. The clearance rate of honokiol was also shortened about 2-fold in comparison with pure honokiol when encapsulated into the micelles. These results suggest that the developed F127-cyclodextrin micellar formulation is a promising drug delivery system for antifungal drugs.