Determination of Photoprotective Capacity of Topical Gel Formulations Containing Bioactive Compound Rutin and Evaluation of Physicochemical Stability

A series of skin damages are mediated by excessive exposure to ultraviolet B (UVB) radiation. Chemical UV filters can cause photodegradation and adverse effects on the skin. Rutin is a natural multifunctional nutraceutical that can prevent damage from sun radiation. This compound is found in fruits, vegetables, and grains. Previous studies have reported rutin as a good antioxidant and photoprotective agent in sunscreen formulations. This work focused on the development of a formulation and evaluation of the protective activity of rutin as a single compound in sunscreen preparations. The Design Expert software was used for formulation optimization. Photoprotection testing was conducted in vitro by observing the parameters of Sun Protection Factor (SPF), percentage of erythema transmission, and pigmentation. Freeze-thaw cycling test and storage at room temperature were performed to evaluate the stability of the formulation. The optimum formula has good characteristics with a pH value of 6.207±0.013, viscosity of 76.5±0.1, spreadability of 10.82±0.440, and adhesiveness of 1.280±0.027. This sunscreen formulation provided a high level of protection with a sun protection factor (SPF) value of 38.11±0.082. The percentage of erythema and pigmentation transmission fell within the sunblock category. Although there were variations in the SPF values when rutin was formulated into the sunscreen, the overall quality of protection was not compromised. The physical and chemical properties of this sunscreen formulation remained stable after stability testing.