Optimization of SRC (Semi Refined Carrageenan) and Glucomannan Concentration as Gelling Agent to the Physical Stability Sunscreen Gel of Dry Corncob Extract (Zea mays L.).

Corncob is one of crude drug which containing phenolic compounds that can be used as an active ingredient for sunscreen preparations. In this study, extracts of dried corn cob made into a gel formulation using SRC (Semi Refined Carrageenan) and glucomannan as a gelling agent.This study aims to determine the optimal concentration of SRC (Semi Refined Carrageenan) and glucomannan to the physical stability of the gel.Gel made into four formulas with a ratio of 1: 4 and the concentration of each formula was 1%, 1.5%, 2%, 2.5%. Each formula was evaluated for 6 weeks of storage that includes organoleptic test, homogeneity, pH, viscosity, dispersive power, freeze-thaw test and centrifugation.The results showed the fourth formula did not change the organoleptic test and homogeneity test. In the test separation of the freeze-thaw method, the fourth formula was stable, while in the centrifugation test formula 1 and 2 was been separation. pH and viscosity results obtained from statistics with a two-way ANOVA showed significant differences in each formula.From the results of this study concluded that the formula 3 with a concentration of 2% was the optimal concentration as a gelling agent.