The Effect of Increasing Solubility with Cosolven and PVP on the Preparation and Characterization of Brown Seaweed Extract (Sargassum Polycystum) Nanoparticle as Antioxidants

Brown seaweed (Sargassum polycystum) is one of the seaweed groups that has high antioxidant activity. This activity comes from Fucoxanthin, a caotenoid-derivative molecules. The objective of the study is improving solubility of brown seaweed extract in aiming to make a stable and meeting the requirement of nanoparticle characterization test. Brown seaweed was extracted then the solubility of brown seaweed extract was increased by using the cosolvent and solid dispersion method. The formula with best solubility test results then be used in the process of making nanoparticles by ionic gelation method by using chitosan as a polymer and sodium tripolyphosphate as a crosslinker agent. Brown seaweed extract was dried by freeze drying method. Then it became powdered brown seaweed extract nanoparticles. From this study, it was obtained that the particle size and the potensial zeta of cosolven-based nanoparticle and PVP-based nanoparticles were 226.2 nm and 50.40 mV ; 365.1nm, and 26.56 mV, respectively. The morphology of brown seaweed extract nanoparticles were spherical and amorphous which was supported by TEM and XRD results. Then an antioxidant activity test was carried out by using the ABTS method. IC50 values of brown seaweed extract, cosolvent-based and PVP-based nanoparticles were 93.98 ppm, 98.72 ppm, and 97.63 ppm, respectively. This study showed that there was significant differences of antioxidant activity between brown seaweed extract, cosolven-based nanoparticle, and PVP-based nanoparticles (one-way ANVA (0.000) less than 0.05).