Polyherbal Sunscreen Cream: Formulation, Physicochemical Evaluation, And In Vitro SPF Determination

Background: Herbal bioactives with antioxidant and UV-protective properties are increasingly favored in sunscreen formulations for their safety and efficacy. This study focuses on the development and optimization of a polyherbal sunscreen cream incorporating Camellia sinensis (green tea), Citrus sinensis (orange peel), Punica granatum (pomegranate peel), Curcuma longa (turmeric) extracts in an oil-in-water emulsion base. Objective: To formulate and evaluate a stable, non-greasy polyherbal sunscreen cream and identify the optimal formulation in terms of SPF, texture, spreadability, and stability. Methods: Three formulations (F1–F3) were prepared using a fixed base of stearyl alcohol, cetyl alcohol, emulsifying wax, olive oil, glycerin, and parabens, with varying concentrations of herbal extract blend (6% to 10% w/w). The creams were evaluated for physical characteristics, pH, viscosity, spreadability, in-vitro SPF, and stability under accelerated conditions (centrifugation, thermal cycling, and long-term storage). Results: All formulations were smooth, yellow-green, optically homogeneous, and free from grittiness. pH values remained skin-compatible (6.05–6.15), and no phase separation was observed during stability testing. F3, containing the highest concentration of polyherbal extract and oil phase, exhibited the highest SPF value of 22.7 ± 0.6, a viscosity of 17,600 ± 210 cP, and a spreadability of 5.2 ± 0.2 cm, indicating a rich texture with high photoprotective capacity. All formulations passed centrifugation and thermal cycling tests and maintained long-term stability over 90 days. Conclusion: Among the three tested formulations, F3 was found to be the most effective due to its superior SPF value, acceptable spreadability, and excellent stability. This study highlights the potential of polyherbal extracts as safe and effective ingredients in natural sunscreen formulations, suitable for further in vivo testing and commercial development.