Mucoadhesive polymers can interact with the mucus layer covering on the intestinal epithelium, providing a longer residence time for the particles at the absorption sites, and allowing more drug cargos to release from the particles for better therapeutic effect.11 Generally, mucoadhesive polymers are hydrophilic macromolecules with numerous hydrogen bond groups. The interaction between the mucus and the mucoadhesive is exactly based on hydrogen bonding as well as electrostatic interactions between the positively charged polymers and negatively charged residues of the mucus layer.Some typical polymers, such as carbomers, chitosan, polyacrylic acid (PAA), sodium alginate, and cellulose derivatives, have been used as mucoadhesives.