title: The design of pH-sensitive chitosan-based formulations for gastrointestinal delivery.
abstract: Chitosan, a nontoxic and biocompatible polysaccharide, has been widely explored for the gastrointestinal delivery of drugs, proteins, peptides and genes for different therapeutic purposes. Because a pH gradient exists in the gastrointestinal tract, chitosan-based formulations in response to specific pH conditions, such as the low pH in the stomach and a high pH in the intestine, have been developed as a general strategy for disease diagnosis and therapy. Tailored pH-responsive drug release in the gastrointestinal tract can be achieved with various chitosan-based formulations such as nanoparticles, microspheres, hydrogels and nanocomposites. This review focuses on the most recent development of chitosan-based pH-sensitive formulations for gastrointestinal delivery, covering various types of chitosan-based formulations, their pH-responsive mechanisms and biomedical applications.
authors.affiliation: College of Pharmaceutical Sciences, Shandong University, Jinan 250012, China.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Du
authors.affiliation: College of Pharmaceutical Sciences, Shandong University, Jinan 250012, China.
authors.forename: Mengrui
authors.initials: M
authors.lastname: Liu
authors.affiliation: College of Pharmaceutical Sciences, Shandong University, Jinan 250012, China.
authors.forename: Xiaoye
authors.initials: X
authors.lastname: Yang
authors.affiliation: College of Pharmaceutical Sciences, Shandong University, Jinan 250012, China. Electronic address: professorgxzhai@aliyun.com.
authors.forename: Guangxi
authors.initials: G
authors.lastname: Zhai
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002626:Chemistry, Pharmaceutical; D048271:Chitosan / Q000737:chemistry*; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D005750:Gastric Juice / Q000737:chemistry; D065569:Gastrointestinal Absorption; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007419:Intestinal Secretions / Q000737:chemistry; D004364:Pharmaceutical Preparations / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism; D013678:Technology, Pharmaceutical / Q000379:methods
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004364:Pharmaceutical Preparations; D048271:Chitosan