Preparation & Evaluation of Lip Stain Cosmetics with Improved Longevity and Hydration

Lip stain is a cosmetic product formulated to impart color to the lips while ensuring a natural, sheer, and long-lasting effect. This study aims to develop lip stain cosmetics with enhanced longevity and evaluate their performance. We formulated a lip stain incorporating sodium polyglutamate crosspolymer, hyaluronic acid, and glyceryl glucoside to improve durability and moisturizing properties. The stability of the formulations was assessed through centrifugation and thermal cycling tests. To evaluate safety and efficacy, thirty Korean female volunteers in their twenties, with no adverse clinical history related to lip products, were enrolled in this study. The results indicated that the stability of the lip stain formulation was confirmed via centrifugation and cycling tests. The cumulative irritation test results showed that none of the participants exhibited any adverse reactions, confirming the cosmetic’s safety. These findings provide valuable data supporting the safety of the lip stain for repeated use. Finally, the durability assessment demonstrated a statistically significant increase in redness after 8 hours, indicating the manufactured lip stain’s excellent durability. This study presents the potential for developing functional lip makeup cosmetics with improved longevity properties.