Compartment

pH

Polymer of interest

Extracellular fluid

7.34~7.45

Poly (aspartic acid)

Saliva

6.0-7.0

Xanthan gum

Stomach

1.5-2.0

Guar gum, Sodium alginate, Chitosan

Duodenum

3.0-5.0

Chitosan

Small intestine

6.0-8.0

Eudragit S100, cellulose-based polymer

Large intestine

5.5-7.0

Eudragit S, L

Extracellular tumor

6.5-7.4

Cellacefate, Eudragit L

Inflamed tissue

6.0-6.8

Sodium Alginate

Cardiac ischemia

5.7

Polypyrrole chitosan, Polyaniline