Formulation and testing of SPF (Sun Protection Factor) value sunscreen gel from ethanol extract of bilimbing wuluh fruit (Averrhoa bilimbi L.) in vitro

Sunscreen is a cosmetic preparation formulated to reduce and protect the skin from the adverse effects of exposure to ultraviolet light. Bilimbi fruit is one of the plants that potential as a sunscreen, because it contains flavonoid groups that can absorb and reduce the intensity of ultraviolet light exposure. The purpose of this study was to formulate and test the potential SPF value of sunscreen gel preparation of bilimbi fruit extract. This research used experimental method, by making 3 variations of gel formula such as F1 (5% extract), F2 (10% extract), and F3 (15% extract). The physical properties of the gel were tested (homogeneity, organoleptic, spreadability, adhesiveness, pH, and viscosity), and the SPF value was tested in vitro with a UV-Vis spectrophotometer. The results of the physical properties test showed that the bilimbi fruit extract sunscreen gel produced a gel that met the requirements of physical properties of a good gel preparation, while from the SPF value test results it was known that all gel formulas had potential as sunscreens. Where F1 gel has an SPF value of 13.43 (maximum protection), F2 has an SPF value of 15.92 (ultra protection), and F3 has an SPF value of 17.24 (ultra protection). Keywords: Averrhoa bilimbi L., formulation, sunscreen, SPF