Table 1.

Defining different variables and their respective Box-Behnken design levels for optimizing pHLip formulation.

Variables	Levels
	−1	0	+1
Independent variables
A = Molar ratio of E80:DOPE	2:3	3:2	4:1
B = Molar conc. of CHEMS	1	2	3
C = Drug amount (mg)	2.5	5	7.5
Dependent variables	Constraints
Y1 = Particle size (nm)	Minimum
Y2 = Entrapment efficiency (%)	Maximum Maximum
Y3 = pH sensitivity (%)