Table 1 Response optimization of 2⁵ full factorial design for RP-HPLC separation of OMG/MET/EZT mixture

K‘_OMG

Maximize

0.15

0.16

-

1

1

0.1715

1.0

Rt_OMG

Target

4.1

4.15

4.2

1

1

4.15

0.9938

T_10%OMG

Minimize

-

1.15

1.18

1

1

1.1358

1.0

Rt_MET

Maximize

4.8

4.9

-

1

1

4.892

0.9250

T_10%MET

Minimize

-

2.15

2.25

1

2

2.15

1.0

Rt_EZT

Target

6.5

7.5

8

1

1

7.518

0.9624

T_10%EZT

Minimize

-

1.2

1.45

1

1

1.265

0.7393

Optimum conditions: Organic modifier % = 67%, buffer conc.= 6.6 mM, pH = 7.0, temperature = 45 °C, flow rate = 0.814 mL/min

Composite desirability (D) = 0.9483