Table 1.

3².2¹ full factorial design manipulated for optimization of the piperine-loaded bilosomal formulae.

Factors (independent variables)	Levels
X1: Type of surfactant	Span 65	Brij 72	Brij78
X2: Surfactant:cholesterol ratio	9:1		1:1
X3: Concentration of bile salt (%)	1	2.5	5