<![CDATA[Background: Skin damage caused by ultraviolet light and free radicals is a growing health problem in tropical countries such as Indonesia. The demand for natural skin care products with high antioxidant and moisturizing effects has driven the development of vegetable oil-based formulations.Objective: This study aimed to analyze the effects of varying concentrations of moringa seed oil on the physical characteristics and stability of lotions formulated with a combination of moringa seed and sunflower seed oils.Methods: This study used a completely randomized laboratory experimental design (CRD). Four formula variations were created with varying moringa seed oil concentrations: 0%, 6%, 9%, and 12%, with a fixed sunflower seed oil concentration of 5%. Physical quality evaluation included organoleptic tests, homogeneity, pH, spreadability, and stability testing for 28 days at temperatures of 25-30°C. Data were analyzed using a one-way ANOVA at a significance level of 0.05.Results: All formulas produced a homogeneous lotion preparation with a pH ranging from 5.2–5.6 and a spreadability diameter between 5.8–6.8 cm, which are within the standard range for topical preparations. Statistical analysis showed that increasing the concentration of moringa seed oil significantly affected the pH and spreadability of the lotion (p < 0.05), but did not affect homogeneity. Over 28 days of storage, no significant changes were observed in the physical parameters, indicating good stability of the preparation. Theoretically, this study strengthens the oil-water phase equilibrium model in the emulsion structure. At the same time, practically, the results contribute to the development of natural cosmetic products based on local ingredients that are safe, effective, and highly competitive in the cosmetic industry market.Conclusion: The results of this study indicate that moringa seed oil has the potential to be used as a natural active ingredient in cosmetic lotion formulations based on local natural ingredients. A limitation of this study lies in the short storage time. Further research is recommended to include long-term stability tests and quantitative analysis of antioxidant activity to strengthen empirical evidence of the formulation's effectiveness.]]>
