<![CDATA[Mosquito-borne diseases remain a major public health concern in tropical regions, necessitating safer and environmentally friendly alternatives to synthetic repellents. This study aimed to formulate and evaluate a natural mosquito-repellent lotion containing (Cinnamomum burmannii and Pogostemon cablin essential oils. A completely randomized experimental design was applied using four formulations (F0–F3) with varying concentrations of cinnamon oil (15–25%) and a fixed concentration of patchouli oil (7%). Physicochemical properties, including pH, viscosity, spreadability, adhesion, and stability, were evaluated, and repellent activity against Aedes aegypti was assessed using an arm-in-cage method. All measurements were conducted in triplicate and analyzed using one-way ANOVA. The results showed that all formulations met acceptable cosmetic standards, with pH values ranging from 5.8 to 7.92, viscosity between 7.560–12.420 cP, spreadability of 5.2–7.1 cm, and adhesion time of 5.0–12 s, while maintaining stable emulsion characteristics. Repellent efficacy increased with oil concentration, with the optimal formulation (F3: 25% cinnamon + 7% patchouli) achieving 80% protection, approaching the DEET control (90%). These findings indicate that the combination of cinnamon and patchouli essential oils has strong potential as a natural, safe, and sustainable mosquito repellent. The formulation was optimized based on physicochemical stability and repellent activity. Further optimization using advanced delivery systems, such as nanoencapsulation, is recommended to improve efficacy and durability. ]]>
