Preparation and gastrointestinal absorption kinetics of tacrolimus solid dispersion

To prepare tacrolimus solid dispersion to increase the solubility and bioavailability of tacrolimus. Tacrolimus solid dispersions were prepared by different water-soluble carriers, which were evaluated by in vitro drug dissolutions to select the optimal formulation. The optimal tacrolimus solid dispersion was evaluated by scanning electron microscopy(SEM), X-ray diffraction(XRD)and differential scanning calorimetry(DSC), and its gastrointestinal absorption kinetics was studied in rats. The results showed that tacrolimus solid dispersion with HPMC E3 as carrier had the fastest dissolution rate. SEM, XRD and DSC studies indicated that tacrolimus was distributed within the carrier HPMC E3 in amorphous form. Gastrointestinal absorption experiments in rats demonstrated that the optimal formulation remarkably increased oral absorption of tacrolimus. These results demonstrate that a novel tacrolimus solid dispersion with HPMC E3 as carrier may be an advantageous dosage form of tacrolimus, boosting the solubility and absorption in gastrointestinal tract.