Development and Assessment of Herbal Sun Protective Lip Balm Incorporating with Chia Seed Oil and Virgin Coconut Oil

Background: The lips are highly vulnerable to ultraviolet radiation because of their thin epithelium, low melanin and continuous environmental exposure. Conventional lip balms often contain synthetic UV filters and petrochemical excipients which may cause irritation and long-term safety concerns, leading to increasing the natural alternatives. Objectives: The aim of this study was to formulate and evaluate an herbal sun protective lip balm using chia seed oil and virgin coconut oil as natural functional ingredients. Materials and Methods: Lip balm formulations were prepared by different concentrations of chia seed oil and virgin coconut oil while maintaining the total lipid base constant. The formulations were evaluated for organoleptic characteristics, pH, melting point, spreadability and in vitro Sun Protection Factor (SPF). SPF was determined by using UV-visible spectrophotometry based on the Mansur method in the wavelength range of 290-320 nm. Results: All formulations exhibit acceptable physical characteristics, smooth texture, uniform appearance, acceptable pH, and good spreadability. In vitro SPF values ranged from 28.8±1.0 to 34.2±1.1, indicating moderate to high UV protection. Formulation F5 showed the highest SPF value (34.2±1.1), which may be attributed to the antioxidants and rich omega-3 fatty acid composition of chia seed oil and the moisturizing properties of virgin coconut oil. Conclusion: The study demonstrates that chia seed oil and virgin coconut oil can be effectively used in herbal lip balm formulations to provide photoprotective and moisturizing effects, offering a safer natural alternative to synthetic lip care products.