Development and Evaluation of Herbal Sunscreen Using Rhododendron barbatum Flower Extract

The damaging effects of ultraviolet (UV) radiation on the skin include skin burns, photoaging, hyperpigmentation, and skin cancer. Sunscreens are extensively utilized for UV protection. Herbal sunscreens have recently been considered because of their safety, antioxidant potential, and fewer side effects. The flowers of Rhododendron barbatum contain flavonoids, phenolics, tannins, and saponins that impart photoprotective properties to the flowers. Hydroalcoholic extraction was carried out using a maceration process, where ethanol and water were used in 70:30 ratio. The phytochemical analysis was undertaken on R. barbatum flowers. Three different formulations were used (F1, F2, and F3) containing 1ml, 2ml and 3ml hydroalcoholic extract. These were screened against various parameters, including colour, pH, spreadability, washability, stability, and patch tests, and SPF determination using the Mansur equation. The phytochemical analysis indicated the presence of flavonoids, phenols, tannins, and saponins. All experiments were done in triplicates (n = 3), and all results were calculated as mean ± SD. All formulations displayed desirable physicochemical characteristics. Among all formulations, F3 displayed the best characteristics in terms of homogeneity, spreadability, and stability. The pH of F3 was found to be 5.60 ± 0.17 and its spreadability was 5.50 ± 0.00 cm (mean ± SD, n = 3), which is favorable for topical application. The SPF value of formulation F3 was 8.36. The SPF activity is due to the presence of flavonoids and phenols that exhibit good antioxidant properties and UV absorptive properties. This helps prevent oxidative stress and UV-induced damage. The enhanced activity exhibited by formulation F3 can be attributed to the higher concentration of extracts present in this formulation. The herbal sunscreen cream was chemically and physically stable, safe, and showed moderate photoprotective efficacy. Therefore, it can be considered an alternative to artificial sunscreen creams. The developed formulation may serve as a promising natural sunscreen. However, further in vivo and clinical evaluation are required. Keywords: Herbal sunscreen, Rhododendron barbatum, Ultraviolet radiation, SPF, Flavonoids, Photoprotection