title: [Study on in vitro colon-specific enzymatic degradation performance of carboxymethyl konjac glucomannan].
abstract: OBJECTIVE
  In vitro enzymatic degradation of carboxymethy konjac glucomannan (CMKGM) were studied to evaluate the feasibility of CMKGM used as carrier materials to prepare colon-specific drug delivery systems.
  
  
  METHODS
  The solutions with rat gastrointestinal tract (GIT) contents or with commercial enzymes were chosen to stimulate in vivo GIT environment, respectively. Enzymatic degradation of CMKGM were studied by viscometic procedure. Degradation kinetics of CMKGM and konjac glucomannan (KGM) by enzymes, the effects of the degree of substitution (DS) of CMKGM and the pH of solution on its susceptibility to degradation were investigated.
  
  
  RESULTS
  CMKGM were degraded mainly in the simulated cecal and colonic media, but not in the simulated gastric and enteric media. Degradation of KGM and CMKGM by enzymes obeyed Michaelis-Menton kinetics. CMKGM with lower DS were more susceptible substrates. CMKGM were more susceptible substrates in solution with pH 6. 0-6. 8.
  
  
  CONCLUSIONS
  CMKGM had colon-specific enzymatic degradation characteristics and could be used as carrier materials to prepare colon-specific drug delivery systems.
authors.affiliation: School of Pharmacy, Henan University, Kaifeng 475004, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ya-Ling
authors.initials: YL
authors.lastname: Wu
authors.forename: Shi-Xiang
authors.initials: SX
authors.lastname: Hou
mesh_terms: D031056:Amorphophallus / Q000737:chemistry*; D000818:Animals; D002432:Cecum / Q000201:enzymology; D003106:Colon / Q000201:enzymology*; D004337:Drug Carriers / Q000737:chemistry; D016503:Drug Delivery Systems; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008351:Mannans / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D010946:Plants, Medicinal / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D044902:beta-Mannosidase / Q000378:metabolism*
chemical_list: D004337:Drug Carriers; D008351:Mannans; C538690:carboxymethyl konjac glucomannan; C022901:(1-6)-alpha-glucomannan; D044902:beta-Mannosidase