Optimization of Rosella Extract-based Antioxidant Peel-off Mask Using Simple Lattice Design

The skin is highly vulnerable to damage caused by free radicals, which disrupt biological components and accelerate aging. While endogenous antioxidants provide some protection, external sources are often needed. Rosella (Hibiscus sabdariffa L.) is a rich source of flavonoids and astaxanthin, proven antioxidants that inhibit matrix metalloproteinase-1, prevent collagen degradation, and reduce ultraviolet-induced damage. The aim of the study was to optimize the formulation of a peel-off mask, incorporating Rosella extract as an antioxidant.

Rosella extract was analyzed using liquid chromatography-mass - mass spectrometry (LC-MS) to identify its antioxidant components. Freeze-dried Rosella powder was granulated and incorporated into a gel mask using polyvinyl alcohol (PVA) or gelatin as the base polymer. Formula optimization was conducted using simplex lattice design and evaluated for physical properties, antioxidant activity, and stability.

LC-MS analysis detected astaxanthin, quercetin, rutin, and kaempferol in Rosella extract. Granulated Rosella exhibited good flowability and a particle size distribution of 250-425 μm. The optimized formula was PVA-based, containing 12.5% PVA and 7.5% propylene glycol. The product demonstrated desirable physical properties, including a drying time of 5.29 minutes, a pH of 5.32, a spreadability of 5.34 cm, an adhesivity of 6.86 seconds, and a viscosity of 30,658 cP. Stability tests confirmed the formula remained stable for 3 months, under room temperature, freeze-thaw cycles, and centrifugation. The final product, containing 15% Rosella, exhibited 45.33% antioxidant activity.

The PVA-based Rosella peel-off mask demonstrated optimal physical properties, stability, and antioxidant properties, offering a promising approach to incorporating antioxidants into cosmetic formulations.