Development of a Lip Scrub Formulation Based on Sappan Wood Bark Extract (Caesalpinia sappan L.) as a Natural Antioxidant Source

Sappan wood (Caesalpinia sappan L.) contains high levels of phenolic compounds, particularly brazilin and flavonoids, which offer strong natural antioxidant potential. Evaluating its bioactivity and physicochemical stability after processing is essential for cosmetic applications. This study developed a lip scrub formulation containing sappan wood bark extract as a natural antioxidant source and evaluated its physicochemical properties and antioxidant activity. Botanically authenticated raw material was extracted using a digestion method with water, followed by concentration. The extract was evaluated for organoleptic properties, pH, drying loss, and DPPH radical scavenging activity. Three lip scrub formulations with varying extract concentrations were evaluated for organoleptic properties, homogeneity, spreadability, pH, DPPH antioxidant activity, and total flavonoid content using the aluminum chloride colorimetric method. The extract showed very strong antioxidant activity with an IC50 of 15.25 ± 0.03 μg/mL and a total flavonoid content of 35.2551 mg QE/g. All formulations exhibited acceptable physical characteristics and pH values safe for lip application. The formulations maintained very strong antioxidant activity, with IC50 values of 26.73 ± 0.07 μg/mL, 26.65 ± 0.08 μg/mL, and 26.56 ± 0.01 μg/mL for Formulas I, II, and III, respectively. Formula III demonstrated the lowest IC50 value and the highest flavonoid content. Although processing slightly reduced antioxidant capacity compared to the crude extract, the formulations successfully retained significant antioxidant activity, confirming sappan wood bark extract as a promising natural ingredient for functional lip care products.