The Characterization and Testing Liquid Soap Nanoparticles of Tamarillo Extract as Antioxidants W Wirasti 1 , Yulian Wahyu Permadi 2 , Wulan Agustin Ningrum 3 {wirasti.kharis@gmail.com 1 } Pharmacy, Universitas Muhammadiyah Pekajangan Pekalongan, 51172, Indonesia 1,2,3 Abstract. The technology of nanoparticles is a formulating technology of a particle which dispersed on the nanometer size or scale per thousand microns. This study aims to characterization and produce the liquid soap preparation from nanoparticles of ‘terong belanda’ extract which is very good for the antioxidants. This technology has very significant effect as the antioxidants, so it possibly produced as cosmetic ingredients. The extraction method used here is maceration using of methanol solvent. Meanwhile, the making of technology of ‘terong belanda’ extract nanoparticles used biopolymer-based nanoparticle method. It was formulated as a liquid soap. The result of particle size analysis is extract nanoparticle for about 183,4 μm, the size of the nanoparticles in liquid soap has achieved 186.2 μm. Moreover, the result of antioxidants activity test which was conducted by the free radical scavenger method of DPPH obtained IC50 nanoparticle liquid soap preparation of 47 mg/ml, compared with scorbut acid IC50 at 49 mg/ml. Water content liquid soap nanoparticles tamarillo extract is 7,4% Besides, the results of the stability test for liquid soap nanoparticles, consisting pH 8.3- 8.6, viscosity (3928 – 3930 poise), Foam stability power test is 85.87 and 89%, stated there is no consistency changing of each formula. From organoleptic test, it resulted a light yellow from ‘terong belanda’ color, a characteristic soap odor and a physical condition with thick / semi-solid consistency. The last, it could be concluded from the nanoparticles liquid soap testing; there is no changing of nanoparticles size. However, it resulted a strong antioxidant power and the stability of the preparation meets the SNI requirements. Keywords: Liquid soap nanoparticles, Tamarillo extract, Antioxidants 1 Introduction Tamarillo fruits is a domestic commodity that has good potential to be developed. Therefore, research is needed to make use of tamarillo so that it is easily distributed and promoted. This fruit is mostly consumed as fruit, whether it is used fresh, made in syrup, or juice. Other than that, may be useful for cosmetics. The use of cosmetic preparations in the form of nanoparticles is developing. The technology of nanoparticles is a formulating technology of a particle which dispersed on the nanometer size or scale per thousand microns. This study aims to characterization and produce the liquid soap nanoparticles of tamarillo extract as antioxidants. This study aims to characterization and produce the liquid soap nanoparticles of tamarillo extract as antioxidants. The contribution of this research is development of nanoparticles in natural ingredients that are useful for cosmetics, thus increasing innovation in cosmetic preparations. The use of cosmetic preparations of nanoparticles is still possible to develop more widely, considering that BIS-HSS 2020, November 18, Indonesia Copyright © 2021 EAI DOI 10.4108/eai.18-11-2020.2311660