Solubility is an important physicochemical property affecting drug bioavailability. One approach to improve drug solubility is using amorphous formulations, which can improve solubility by up to a 1000-fold. Herein, amorphous curcumin (CUR) and amorphous solid dispersions (SDs) consisting of CUR, hydroxypropyl cellulose (HPC) and/or sodium dodecyl sulfate (SDS) were developed using vibrational ball milling. The resulting ground mixtures (GMs) were characterized using powder X-ray diffractometry, Fourier transform infrared spectroscopy, differential scanning calorimetry and a dissolution test. The 60-min GM containing 90% HPC significantly increased the drug solubility. Presence of SDS in the GMs containing 90% HPC reduced the grinding duration from 60 min to 30 min in forming a ground SD that significantly increased the CUR dissolution rate. This amorphous state was stable for 30 days when stored at 40 °C/RH 75%.
Keywords: Fourier transform infrared spectroscopy; X-ray powder diffraction; amorphous solid dispersion; differential scanning calorimetry; dissolution; poorly water-soluble drug; solubility; stability; vibrational ball milling.