Table 1.

Independent variables’ levels (coded and actual) in the central composite design and desirability constraints of the measured size of AG-PTMs.

Factoars	Levels
	–1	0	+1
X1: AG:PC molar ratio	1:1	1:3	1:5
X2: Sonication time (min)	1	3	5
Response	Desirability constraints
Y: Particle size (nm)	Minimize

AG, andrographolide; PTM, Phytosomes; PC, phosphatidyl choline.