DEVELOPMENT OF A GUAR/GELATIN MATRIX CONTAINING LIGNIN DERIVATIVES AND VACCINIUM VITIS-IDAEA EXTRACT FOR COSMETICAL USE

This study developed guar gum-gelatin matrices incorporating Lignoboost lignin, lignin esterified with aspartic acid, lignin esterified with succinic acid, and Vaccinium vitis-idaea (Vv) extract for potential skincare applications. Fourier-transform infrared spectroscopy, 13C nuclear magnetic resonance spectroscopy, and X-ray photoelectron spectroscopy confirmed successful lignin esterification. Mechanical testing showed that lignin derivatives increased elongation at break (up to 28.15 mm for lignin-containing films), while generally reducing tensile strength compared to the plain matrix (2.79 MPa). The addition of Vv extract reduced flexibility, with lignin succinate-Vv showing the lowest elongation (12.80 mm) and tensile strength (0.37 MPa). The release of lingonberry extract followed the Weibull model (R2 values between 0.976–0.996), with diffusion-controlled kinetics. Lignin succinate-Vv achieved the highest release (30.30 mg/g), while lignin-Vv enabled prolonged delivery (~42% release). Anti-inflammatory activity exceeded 58% inhibition of albumin denaturation for lignin succinate-Vv films, and all formulations maintained over 94% fibroblast viability.