<![CDATA[To protect the skin, a practical skin care product called a spray liquid is essential. This product moisturizes and refreshes the skin. The leaves of Melastoma malabathricum L. contain secondary flavonoid metabolites such as quercetin and kaempferol, which exhibit antioxidant activity and potential as sunscreen agents. The Natural Deep Eutectic Solvents (NaDES) extraction method was employed as an environmentally friendly solvent alternative to obtain optimal extracts. This study aims to formulate a sunscreen spray liquid from senduduk leaf extract using NaDES solvents and evaluate the physical properties, safety, and sunscreen activity of the formulation. The senduduk leaf extract was obtained through ultrasonic extraction using a NaDES solvent mixture of choline chloride and lactic acid. The spray liquid formula was prepared with extract concentrations of 0%, 3%, and 6%. Evaluations were conducted on organoleptic properties, homogeneity, pH, viscosity, spray spreadability, stability, irritation, preference, in vitro sunscreen activity using UV-Vis spectrophotometry, and Particle Size Analysis (PSA). The results indicated that all formulas were organoleptically stable during six stability cycles with a pH of 4.8–5.0, viscosity of 2.43–5.23 cP, and spray spreadability of 5.08–5.87 cm. The irritation revealed no irritation reaction in ten respondents. Formula F2 demonstrated an SPF value of 27.08 (ultra protection) with a particle size of 14.2 nm. The conclusion of this study is that the spray liquid formulation utilizing NaDES solvent meets physical evaluation parameters, is safe for use, and possesses sunscreen activity.]]>
