Table 5.

Summary results of regression analysis for responses.

Response	F-Value	R2	R2adjusted	R2predicted	Lack of Fit	Remark
Response Y1 (Particle Size)
Linear	81.84	0.9571	0.9454	0.9217	0.0198	-
2FI	68.61	0.9809	0.9666	0.9553	0.0296	-
Quadratic	820.04	0.9993	0.9981	0.9918	0.3893	Suggested
Statistically significant factors for Y1 (p < 0.05) is X1, X2 and X3
Response Y2 (zeta potential)
Linear	6.29	0.6316	0.5311	0.3324	0.0314	-
2FI	6.24	0.8238	0.6917	0.5719	0.0437	-
Quadratic	125.28	0.9840	0.9552	0.8790	0.7375	Suggested
Statistically significant factors for Y2 (p < 0.05) is X1 and X2
Response Y3 (LE)
Linear	10.89	0.7482	0.6795	0.5963	0.0197	-
2FI	4.18	0.7580	0.5765	0.2817	0.0137	-
Quadratic	68.02	0.9919	0.9773	0.8856	0.1982	Suggested
Statistically significant factors for Y3 (p < 0.05) is X1, X2 and X3
Response Y4 (LC)
Linear	0.11	0.0279	−0.2373	−0.8894	0.0030	-
2FI	0.22	0.1404	−0.5043	−2.7683	0.0022	-
Quadratic	685.94	0.9992	0.9977	0.9959	0.9064	Significant
Statistically significant factors for Y3 (p < 0.05) is X1, X2 and X3

Notes: X₁ = CTAB concentration (mg/mL), X₂ = CSO concentration (mg/mL), X₃ = PEG concentration (mg/mL), Y₁ = particle size (nm), Y₂ = zeta potential (mV), Y₃ = LE (%) and Y₄ = LC (%).