Preparation and Characterization of a Curcumin Solid Dispersion with Enhanced Solubility and Hepato-protective Efficacy Against Non-Alcoholic Fatty Liver Disease

Background/Objectives: Curcumin has potential hepatoprotective effects in non-alcoholic fatty liver disease (NAFLD), but its poor aqueous solubility limits formulation development. This study aimed to prepare a curcumin solid dispersion (CSD) using polyvinylpyrrolidone K30 (PVP K30) and phosphatidylcholine to evaluate its physicochemical properties and hepatoprotective effects. Methods: CSD was prepared by solvent evaporation at a curcumin/phosphatidylcholine/PVP K30 weight ratio of 1:2:3. X-ray diffraction, differential scanning calorimetry, Fourier-transform infrared spectroscopy, and scanning electron microscopy were used for characterization. Apparent solubility and in vitro dissolution were assessed in buffers at pH 1.2, 4.5, and 6.8. Raw curcumin and a corresponding physical mixture were used as comparators. Hepatoprotective effects were investigated in a high-fat diet/lipopolysaccharide-induced experimental NAFLD model using serum biochemical markers, hepatic inflammatory cytokines, and liver histology. The animal study compared oral CSD at curcumin-equivalent doses of 50 and 100 mg/kg/day with unformulated curcumin at 200 mg/kg/day. Results: The dispersion showed diffraction and thermal profiles consistent with amorphization of curcumin. Apparent solubility reached 184.2, 232.6, and 292.1 µg/mL at pH 1.2, 4.5, and 6.8, respectively. At pH 1.2, the reported 90 min cumulative dissolution increased from 8.8% for unformulated curcumin to 87.9% for CSD. CSD treatment was associated with lower serum ALT and ALP levels, reduced hepatic lipid accumulation, and decreased hepatic TNF-α, IL-6, and IL-1β levels. Conclusions: The PVP K30/phosphatidylcholine-based solid dispersion improved curcumin's apparent solubility and dissolution and showed hepatoprotective effects in an experimental NAFLD model. These findings support further evaluation of this formulation approach.