Evaluation of Lip Tint Formulation and Antioxidant Activity Assay of Watermelon Fruit Extract (Citrullus lanatus)

Watermelon (Citrullus lanatus) contains vitamins and carotenoids, especially lycopene which functions as a natural red dye so it has the potential to be used as an active ingredient in lip tint. This study aims to formulate watermelon extract as a natural dye and a source of antioxidants in lip tint preparations and to evaluate the quality of the preparations to meet good requirements. This study was conducted experimentally with extract concentrations of 10%, 20%, and 30%. Then the physical properties of the preparations and antioxidant activity were tested. The results showed that all formulas met good physical characteristics, including a homogeneous preparation, a pH of around 5, a spreadability of 2-3 times, and a spreadability at F1 (6.49), F2 (6.57), F3 (6.09), and had maintained stability without changes in color, aroma, or shape, during storage. Antioxidant activity test shows that formula 1 (10%) has antioxidant activity in the very strong category (20.45 ppm), formula 2 (20%) is in the strong category (54.57 ppm), formula 3 (30%) is in the weak category (252.8 ppm). Overall, watermelon extract can be formulated into a good lip tint, but formula 3 (30%) shows lower activity which is thought to be due to the high extract concentration which triggers antagonistic interactions between compounds.