Table 1.

Composition of different coded values in 3³ full factorial design for optimization of simvastatin (SIM) niosomes.

Independent Variable		Code Value
		−1		0		1
surfactant concentration w/v % (X1)		3		4		5
Type of surfactant (X2)		Span 60		Tween 80		Cremophor RH 40
CPC concentration (X3)		0		4		6
Dependent variables	R2	Adjusted R2	Predicted R2	Constraints	p-value	F value	Adequate precision
Y1: EE%	0.6933	0.6677	0.6118	Maximize	0.0001	27.13	10.014
Y2: Vesicles size (nm)	0.9954	0.9899	0.9765	Minimize	0.0001	183.71	43.525
Y3: Zeta potential (mV)	0.7795	0.7611	0.7209	Maximize	0.0001	312.88	11.878
Y4: Q12h (%)	0.9992	0.9983	0.996	Maximize	0.0001	1082.13	103.883

CPC, cetyl pyridinium chloride; EE%, percent of entrapment efficiency; Q12h, cumulative release after 12 h.