Table 1 ICPs and levels of a 24 full factorial design.

From: Formulation, optimization and characterization of allantoin-loaded chitosan nanoparticles to alleviate ethanol-induced gastric ulcer: in-vitro and in-vivo studies

ICPs

Maximum coded level

Minimum coded level

Maximum level

Minimum level

(X1) CS concentration (%, w/v)

 + 1

 − 1

1.5

1

(X2) STPP concentration (%, w/v)

 + 1

 − 1

0.5

0.3

(X3) CS:STPP volume ratio

 + 1

 − 1

5:1

3:1

(X4) ALL amount (mg)

 + 1

 − 1

13

10