Table 2.

Estimated effects of factors and associated p-values for the responses.

Response	Particle size		Polydispersity index		Zeta potential		Entrapment efficiency
	Factor effect	p-value	Factor effect	p-value	Factor effect	p-value	Factor effect	p-value
	Model (Quadratic)	0.0098	Model (Linear)	0.0280	Model (Two-factor interaction)	0.0385	Model (Quadratic)	0.0163
	Lack of fit	0.8739	Lack of fit	0.8171	Lack of fit	0.7392	Lack of fit	0.3490

Factor	Coefficient estimate	p-value	Coefficient estimate	p-value	Coefficient estimate	p-value	Coefficient estimate	p-value
Intercept	160.89		0.5489		−46.23		84.27
X1	38.58	0.0116	–	–	–	–	0.6850	0.3552
X2	–	–	0.2491	0.0280	−3.56	0.0336	1.31	0.0840
X3	–	–	–	–	−2.30	0.1704	2.20	0.0394
X1 X2	–	–	–	–	–	–	2.89	0.0283
X1 X3	−31.02	0.1063	–	–	–	–	7.81	0.0047
X2 X3	42.74	0.0354	–	–	−4.14	0.0705	3.92	0.0124
X12	−42.67	0.0413	–	–	–	–	−0.9787	0.3510
X22	−45.06	0.0332	–	–	–	–	2.00	0.1102
X32	–	–	–	–	–	–	−6.62	0.0050