Improved Stability of trans-Resveratrol in Aqueous Solutions by Carboxymethylated (1,3/1,6)-β-D-Glucan

Resveratrol is a polyphenolic compound endowed with multiple health benefits. However, its limited bioavailability and poor stability in solution hamper its use in pharmaceutical applications. Due to its low solubility in water, solvents such as ethanol and dimethyl sulfoxide are often used to dissolve resveratrol. However, these solvents have adverse effects on cultured cells or in vivo. The purpose of this study was to develop an aqueous liquid formulation of resveratrol in combination with a modified glucan, the carboxymethylated (1,3/1,6)-beta-D-glucan (CM-glucan). The proposed liquid formulation conferred stability to resveratrol without affecting its antioxidant capability. Shelf-life measurements revealed that resveratrol in aqueous solution is degraded within a few weeks, due to spontaneous oxidation. In contrast, the combination with CM-glucan matrix exerted a strong stabilizing effect in aqueous medium and increased resveratrol stability up to 12 months at 25 degrees C. These data provide evidence of a stable resveratrol formulation in liquid suspensions and support the possible development of pharmaceutical applications of this association in biopharmaceutics and drug delivery.