Enhancement of the Aqueous Solubility and Permeability of a Poorly Water Soluble Drug Ritonavir Via Lyophilized Milk-based Solid Dispersions

AbstractIn the present study, a lyophilized milk-based solid dispersion (SD) of ritonavir (RTV) was developed with the goal of improving its aqueous solubility. The SD was prepared by lyophilization, and characterized for its physicochemical and functional properties. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), photomicroscopy and powder X-ray diffraction (PXRD) were used to confirm the formation and robustness of the SD formulation. The prepared SD formulations were functionally evaluated by saturation solubility, in vitro drug release and ex vivo permeation studies. The optimized SD formulation exhibited a significantly higher (30-fold) aqueous solubility (11.36 ± 0.06 μg/mL), compared to the pure RTV (0.37 ± 0.03 μg/mL). The in vitro dissolution studies revealed a significantly higher (∼10-fold) efficiency of the optimized SD formulation in releasing the RTV, compared to the pure RTV. The ex vivo permeation studies with th...