Utilization of Kappaphycus alvarezii and Sargassum plagyophyllum from Banten as cosmetic creams

Kappaphycus alvarezii and Sargassum plagyophyllum are marine commodities from Banten, containing vitamin C, vitamin E and bioactive compounds (alkaloids, terpenoids, steroids, flavonoids, saponins, and tannins), which are thought to have antioxidant and tyrosinase enzyme inhibitory activities. The use of seaweed slurry is chosen because it is cheap, easy to apply and environmentally friendly. The aim of this research was to obtain the selected cream preparation based on antioxidant activity, tyrosinase inhibition and physical characteristics of cream preparation. K. alvarezii and S. plagyophyllum slurry had antioxidant activity (IC₅₀) 598.86±1.494 μg/mL and 595.08±0.995 μg/mL, respectively with L-ascorbic acid 6.56±0.069 μg/mL. The selected cream was formula adding combination slurry of K. alvarezii and S. plagyophyllum (1:1) 20% which had the highest antioxidant activity (IC₅₀) and percent inhibition of tyrosinase enzyme (L-DOPA substrate and 6,000 μg/mL test concentration) 370.44±0.854 μg/mL and 26.139±0.984%, respectively. Cream preparations showed good homogeneity, stable against storage of various temperatures, cycling test, and mechanics with no phase separation and discoloration and pH value of cream fulfilling the pH range of human skin balances and Indonesian National Standard (SNI). Cream preparations did not show significant changes in viscosity value until 8 weeks with the thixotropic plastic rheology.