Effect of Cholesterol to Vitamin D3 and Span 60 to Tween 60 Ratios on the Characteristics of Niosomes: Variable Optimization Using Response Surface Methodology (RSM)

Table 3

Estimated coefficients of multiple determinations (R²) for span using coded values.

Source	Sum of squares	df	Mean square	F-value	value
Model	18.62	5	3.72	235.91	<0.0001	Significant
A-A	0.2421	1	0.2421	15.34	0.0112
B-B	7.65	1	7.65	484.50	<0.0001
AB	1.35	1	1.35	85.26	0.0003
A^2	0.0441	1	0.0441	2.79	0.1556
B^2	8.89	1	8.89	563.57	<0.0001
Residual	0.0789	5	0.0158
Lack of fit	0.0756	3	0.0252	15.33	0.062	Not significant
Pure error	0.0033	2	0.0016
Corrected total	18.69	10

R ²: 0.9958; adjusted R²: 0.9916; predicted R²: 0.9708.