Development and evaluation of chitosan and chitosan/Kollicoat® Smartseal 30 D film-coated tablets for colon targeting

Eur J Pharm Biopharm. 2014 Nov;88(3):807-15. doi: 10.1016/j.ejpb.2014.09.006. Epub 2014 Oct 6.


The aim of the present study was to develop film-coated tablets which release a minor amount of the active pharmaceutical ingredient (API) into the stomach and small intestine, yet show a sharp increase of drug release in the colon. Tablets containing the model drug Diclofenac-Na, microcrystalline cellulose as a filler (MT), as well as tablets consisting of Ludiflash® (LT), both were used as tablet cores, respectively. Either chitosan (CHI) alone or different ratios of chitosan and Kollicoat® Smartseal 30 D (KCSS) were applied onto these cores. The resulting film-coated tablets were analyzed for swelling, drug dissolution and stability. In order to clarify whether the colon release is mainly enzyme-driven or pressure-controlled, the coated tablets were both tested in the colon microflora test (CMT), which simulates the enzyme environment within the colon, and using a bio-relevant dissolution apparatus mimicking the intraluminal pressures and stress conditions present in the gastrointestinal tract (GIT). CHI/KCSS (25:75) coated LTs showed a pressure-controlled site-specific drug release in the large intestine, while remaining intact in the upper GIT. CHI as well as CHI/KCSS (25:75) applied onto MTs, remained stable during the entire simulated bio-relevant dissolution transit of the GIT, but showed enzymatically controlled colon targeting in the CMT. These results could be confirmed for CHI/KCSS (25:75) film-coated MTs top-coated with an additional hydroxypropylmethylcellulose (HPMC) layer and an Eudragit L 30 D-55 (EUL) layer to avoid the dissolution in the fasting stomach.

Keywords: Bio-relevant dissolution; Chitosan; Colon delivery; Colon microflora test; Enzymatic degradation; Film coating; Intraluminal pressure; Kollicoat® Smartseal 30 D.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chitosan / administration & dosage*
  • Chitosan / chemistry
  • Chitosan / metabolism
  • Colon / drug effects*
  • Colon / metabolism
  • Drug Delivery Systems / methods*
  • Drug Evaluation, Preclinical / methods
  • Methacrylates / administration & dosage
  • Methacrylates / chemistry
  • Methacrylates / metabolism
  • Polymers / administration & dosage
  • Polymers / chemistry
  • Polymers / metabolism
  • Polyvinyls / administration & dosage*
  • Polyvinyls / chemistry
  • Polyvinyls / metabolism
  • Swine
  • Tablets, Enteric-Coated


  • Eudragit L 30 D-55
  • Methacrylates
  • Polymers
  • Polyvinyls
  • Tablets, Enteric-Coated
  • polyvinyl acetate
  • Chitosan