249 Magnesium Myristate
OPTIMIZATION OF LIQUID FOUNDATION USING MAGNESIUM MYRISTATE
The 32 factorial design for the two ingredients magnesium myristate (X1) and Liquid
paraffin (X2) which were adjusted at three different levels (coded as -1, 0, and 1), projected
a total of nine trial runs. The response parameters of viscosity (Y1) and spreadability (Y2)
were investigated in this work (Table VII and Table VIII). The residual equations in terms
of coded factors for two dependent variables are shown below.
For dependent variable 1 (viscosity):
Viscosity 2,867.11 A B =+-255.93 39.33 × ×
For dependent variable 2 (spreadability):
Spreadability A B =-+7 52 0.9076 0.2017 .× ×
Figure 3. 3D surface plot showed the effects of concentration of stearic acid, propylene glycol monostearate
and dimethicone on (A) viscosity and (B) spreadability.
Table VII
Predicted Responses for 23 Factorial Design
Analysis Predicted
mean
95% CI low
for mean
95% CI high
for mean
95% TI low
for 99% pop
95% TI high
for 99% pop
Viscosity (cp) 2,754.123 2,714.512 2,793.423 2,489.312 3,018.641
Spreadability (gm.cm./sec) 6.683 6.514 6.461 5.489 7.878
Table VIII
Predicted Responses for 32 Factorial Design
Analysis Predicted
mean
95% CI low
for mean
95% CI high
for mean
95% TI low
for mean
95% TI high
for mean
Viscosity (cp) 2,667.110 2,765.942 2,968.251 2,178.032 2,556.183
Spreadability (gm.cm./sec) 7.925 7.081 7.949 5.557 10.473

250 JOURNAL OF COSMETIC SCIENCE
The relevant factors were identified as concentration of magnesium myristate (X1) and
Liquid paraffin (X2), all of which had a synergistic influence on the response Y1 and Y2
with p values of 0.0060 and 0.0141, respectively.
The 3D surface plot (Figure 4A) showed an increase in viscosity with decreasing
concentrations of both magnesium myristate and liquid paraffin. Figure 4B showed an
Figure 4. 3D surface plot showing the effects of the concentration of magnesium myristate and liquid
paraffin on (A) viscosity and (B) spredability.