The Role of Lipid Composition in the Sensory and Physical Properties of Lipsticks

The perception of lipstick texture upon application is a key driver of consumer satisfaction. However, formulators may only rely on the absence of knowledge about the relationship between ingredients and product sensory properties. Lipsticks are made of a complex anhydrous mixture that contains about 80% lipids (oils, waxes, and butters). The goal of this work was thus to investigate the combined effect of multiple lipid ingredients on the sensory and physical properties of a cosmetic product such as lipstick. To this end, we first analyzed a typical lipstick formula and its related categories of ingredients. This allowed us to create a simplified, yet realistic lipstick system. Based on this, we formulated 36 lipsticks varying in oil and butter composition according to three mixture designs. All products were evaluated by a panel of sensory experts—with a focus on the slipperiness and melting perception—and analyzed using texture measurements. The physical and sensory results both show that the oils had the strongest impact on the lipstick properties while the impact of the butter was negligible. Moreover, the perceived slipperiness of lipsticks was closely related to the viscosity of the oil mixture present in the formula (R² = 0.87). Further analyses of lipstick physicochemical properties by differential scanning calorimetry suggest that the nature and amount of oil influence the crystallization of butter and wax, which could explain the dominant impact of the oils on the sensory and mechanical properties of lipsticks.