Robusta coffee leaves (Coffea canephora) contain antioxidant compounds that can prevent early aging due to free radicals and UV exposure. The purpose of this study is to know the ratio of carbopol and HPMC that can produce a gel formula with good gel physical properties as an antioxidant gel and use the Simplex Lattice Design method and to determine the antioxidant activity in the gel using the DPPH method. 70% ethanol extract gel robusta coffee leaves were made in formulas with variations in carbopol concentration: different HPMCs namely F1 = (0.875% b / b and 1.625% b / b); F2 = (2% b / b and 0.5% b / b); F3 = (1.25% b / b and 1.25% b / b); (1.625% b / b and 0.875% b / b); (0.5% b / b and 2% b / b). The tests carried out are the physical properties of the gel including viscosity, adhesion, dispersion, and pH. The test results are used to determine the optimum gel formula. The conclusion of this study is that the results of the comparison of the optimum gel composition obtained were carbopol 1.35% b / b and HPMC 1.15% b / b with a viscosity value of 2715.34 ± 0.2941 cps, pH 6.57 ± 0.14 , spread power 29.02 ± 1.08 cm2, and adhesion power 162.77 ± and 5.73 seconds it shows that with the combination of carbopol and HPMC the viscosity value will decrease, the pH will be appropriate, the dispersion power will increase and the sticking power will be longer. The test results of antioxidant activity on the optimum formula of 70% ethanol extract of robusta coffee leaves showed strong antioxidant activity against DPPH radicals with ES50 values ​​of 68,547 µg / mL.