Formulation and Evaluation of Resveratrol Solid Dispersion as a Gel

Objective: This study seeks to improve the solubility and dissolution rate of resveratrol (RV), a poorly water-soluble compound, by using the solid dispersion (SD) technique and formulating it as a gel. Methods: Solid dispersions were prepared by solvent evaporation using Nicotinamide (NA) and polyvinylpyrrolidone K30 (PVP K30) as hydrophilic carriers at drug-to-carrier ratios of 1:1, 1:2, and 1:4. The formulations were evaluated for yield, drug content, and saturation solubility. The 1:4 RV: NA formulation showed the highest solubility and dissolution rate and was therefore the most favorable. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) analyses confirmed that resveratrol was amorphous in the solid dispersion. Results: Solubility results show a 2-fold increase in RV solubility of RV by 2-fold for F4 (1:4 RV: NA). The analyses also showed no significant chemical interaction between resveratrol and the carrier; the drug content ranged from 93.3% to 98.3%. The optimized SD was then incorporated into a 1% hyaluronic acid (HA) gel base to formulate gel preparation. This gel demonstrated homogeneity, an appropriate pH, favorable spreadability, and nearly complete drug release within 45 min. Conclusion: These results suggest that nicotinamide-based solid dispersion can effectively enhance resveratrol solubility and dissolution in gel formulations.