Improving the dissolution rate of water-insoluble diflunisal by γ-cyclodextrin metal-organic framework

The aim of this study is to prepare porous γ-cyclodextrin metal-organic framework (CD-MOF) with good biocompatibility to improve the in vitro release properties of water-insoluble drugs. Different sizes of CD-MOF were obtained by controlling the self-assembly of γ-cyclodextrin and potassium ion and the rate of crystal growth. The poorly water-soluble diflunisal (DIF) was selected as the model drug and loaded into the interior of porous CD-MOF by the impregnation method. The DIF loaded CD-MOF (DIF-MOF) was characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), nitrogen adsorption and desorption, Fourier infrared spectrometer and thermogravimetric analysis. In addition, in vitro cytotoxicity and solubilizing capability of CD-MOF were investigated. It revealed that the obtained CD-MOF was cubic-like with a narrow size distribution and high porosity. Negligible cytotoxicity was found after incubation with RAW264.7 cells. Compared with the pure CD-MOF carrier, the morphology and crystal form of DIF-MOF was not damaged during the drug loading process. Moreover, the solubility and release rate of water-insoluble DIF from the DIF-MOF were significantly increased.