Formulation and evaluation of herbal sunscreen using butterfly pea, neem and tulsi extracts

Abstract

Chronic exposure of human skin to ultraviolet (UV) radiation from the sun causes a variety of negative effects, including sunburn, pigmentation, premature aging, oxidative stress, and increased risk of skin cancer. Synthetic sunscreens are widely used to protect the skin from UV rays, but their long-term use comes with several drawbacks, including skin irritation, allergic reactions, phototoxicity, hormonal disruption, and environmental hazards. These limitations have increased global interest in the development of safe, effective, and environmentally friendly plant-based sunscreen formulations derived from natural plant sources. This study aimed to develop and evaluate herbal sunscreens using extracts of Neem (Azadirachta indica), Tulsi (Ocimum sanctum), and Butterfly pea (Clitoria ternatea). These medicinal plants were selected for their well-known antioxidant, anti-inflammatory, antibacterial, and photoprotective properties. Plant materials were collected, authenticated, dried in the shade, and extracted using appropriate solvents. The resulting extract was incorporated into an oil-in-water emulsion base to prepare herbal sunscreens using 
appropriate excipients. The composition of herbal sunscreens was evaluated with respect to various physicochemical and biological parameters including appearance, pH, spread, viscosity, uniformity, stability, sun protection factor (SPF), and skin irritation potential. The pH of the formulation was found to be within an acceptable range for topical use, indicating good skin compatibility. Spreading and viscosity studies revealed satisfactory application properties, ensuring uniform distribution over the entire skin surface. Stability studies confirmed that the drug remained stable without phase separation or degradation under various storage conditions. The presence of bioactive plant components such as flavonoids, phenolic compounds, and anthocyanins significantly contributed to the antioxidant and UV protective activities of the drug. SPF ratings showed effective protection from harmful UV rays, and skin irritation studies found the formula to be non-irritating and safe for topical use.