Formulation code Coded value Actual value
A B C Drug to lipid ratio SurfactantConc. (%) Stirring speed (rpm)
H1 -1 -1 0 1:2 1 2500
H2 1 -1 0 1:4 1 2500
H3 -1 1 0 1:2 2 2500
H4 1 1 0 1:4 2 2500
H5 -1 0 -1 1:2 1.5 2000
H6 1 0 -1 1:4 1.5 2000
H7 -1 0 1 1:2 1.5 3000
H8 1 0 1 1:4 1.5 3000
H9 0 -1 -1 1:3 1 2000
H10 0 1 -1 1:3 2 2000
H11 0 -1 1 1:3 1 3000
H12 0 1 1 1:3 2 3000
H13 0 0 0 1:3 1.5 2500
H14 0 0 0 1:3 1.5 2500
H15 0 0 0 1:3 1.5 2500
H16 0 0 0 1:3 1.5 2500
H17 0 0 0 1:3 1.5 2500
Table 2: Coded and actual values of independent variables.