Exposure of ultraviolet rays which excess can give a bad impact for the skin
health. The harmful effects of UV rays can be overcome by using sunscreen. 2-
hydroxy-4-(octyloxy)benzophenone (HOB) is an ingredient of a sunscreen
chemical, while zinc oxide (ZnO) as a sunscreen physical that can be formulated
in the form of cream. The optimization of formula is used to get an optimum
formula. The aim of this research is to determine the influence of concentration
variation on the SPF values, physical properties of the preparations, and the
optimum concentration that gives the effectiveness of the best sunscreen on the
sunscreen cream. Optimization of formula was done using D-optimal Mixture
Design with 2 independent variables namely the HOB with a limit concentrations
of 5-10% and ZnO of 5-10%. The response in the form of SPF value and
viscosity. The results of test physical properties preparations forms showed that
the observation of the organoleptic, homogeneity, pH, and viscosity fill the cream
physical properties, while the power spread and the adhesion of the cream does
not fill. Response results obtained from the 7 run produce SPF value range of
3,609-8,052, viscosity 7870-8823.33 cps. The results of ANOVA analysis showed
both responses are significant. HOB and ZnO influential in increasing the SPF
and viscosity. The combination of the HOB with ZnO influential in lowering the
SPF and viscosity. The formula of the optimum prediction results from D-optimal
Mixture Design was set with concentration HOB 10% and ZnO 5% with the
prediction of the SPF 7.78 and viscosity 8651.12. The results of the verification
optimum formula use analysis of One-Sample T Test obtained a significant value
more than 0.05 so it is not different significance. The physical stability test of
storage in room temperature is less stable and the physical stability of freeze thaw
cyling occurs in phase separation in cycle-5 and to-6.