<![CDATA[This research had been carried out on the formulation of guava leaf extract nanoemulsion as an active ingredient of antioxidant serum. The steps of this research include: (1) extraction by maceration; (2) Characterization and identification of extracts include phytochemical test, DPPH test, shear reagent test, and identification of compounds using LC-MS/MS; (2) formulation of nanoemulsion using Self-Nanoemulsifying Drug Delivery System (SNEDDS) method; (4) Nanoemulsion testing: stability test, antioxidant activity test using DPPH method, and irritation test, (5) nanoemulsion characterization which includes particle size, transmittance, pH, and viscosity. The results showed that: (1) the extract yields of the maceration method were 15,048%; (2) antioxidant compounds in Guava leaf extract were Candidate Mass C35H42O9, Candidate Mass C26H48O15, Candidate Mass C34H40O9, quercetin dan quercetin-3-O-α-L- arabinopyranoside; The IC50 of the macerated extract were 59,771 ± 1,357 ppm; (3) Nanoemulsions were made in 3 formulas (0.5; 1; and 1,5 g) with fixed variables of capryol 90, tween 20, and PEG 400 (1,5; 2,5; and 1); (4) stability test showed that only F1 was stable; the IC50 value of nanoemulsion is 509,039 ppm; and the F1 irritation test showed no erythema and edema; (5) The particle size of F1 was 168,2 nm with a transmittance value of 96,10%, a pH of 5,45, and a viscosity of 73,88 cP. So that the preparation of guava leaf extract nanoemulsion is not recommended as an active ingredient for making antioxidant serum. Keywords : Guava Leaf, Nanoemulsion, Antioxidant, Serum, SNEDDS]]>
