ABSTRACT
Research to invsetigate the concentration effect of tween-80, span-80, and trietanolamin on cream sunscreen combination of Octyl Methoxycinnamate-Vitamin C and to determine the concentratins of tween-80, span-80, and trietanolaminas emulsion components wich yielded the optimum formula. Determination of cream optimum formula is done by using DX®10 software with simplex design method. The formulas obtained were then tested for their physical characteristic and test result with the formula that approximates the optimum formula prediction of simplex lattice design. In this research the cream formula closest to the prediction of simplex lattice design is formula 4 with 10% tween-80, 3% span-80, and 2% trietanolamin with desirability value 0,880, then tested the activity of sunscreen with the determination of value SPF 22,85 wich is included in the category of maximum protection.

Keywords: Cream sunscreen, Octyl Methoxycinnamate, Optimization, SLD.