title: Ionotropic alginate beads for controlled intestinal protein delivery: effect of chitosan and barium counter-ions on entrapment and release.
abstract: Alginate beads containing the model protein haemoglobin (Hb) were prepared by coagulation with various counter-ions to improve the controlled release of the protein. The effect of Ba(2+) and Ca(2+) ions and of the polycationic polysaccharide chitosan was investigated. Coagulation with Ba(2+), Ca(2+) and/or chitosan showed differences in the swelling index of the beads, in the encapsulation efficiency of Hb entrapment and in the release of the entrapped protein. Chitosan in the coagulation fluid markedly enhanced the encapsulation efficiency of the Hb. Release studies were conducted in simulated gastric fluid (SGF pH approximately or equal to 1.2) and subsequently in simulated intestinal fluid (SIF ) at 37 degrees C. Beads were stable in the gastric fluid but released their protein upon transfer to intestinal fluid. The release coincides with the burst and disintegration of beads. Rate of protein release from the beads was affected by the Ba(2+) and chitosan concentration in coagulation fluid.
authors: Asian Institute of Technology, Klong Luang, Bangkok, Thailand.
authors: D
authors: D
authors: Bhopatkar
authors: A K
authors: AK
authors: Anal
authors: W F
authors: WF
authors: Stevens
mesh_terms: D000464:Alginates; D017609:Barium Compounds / Q000494:pharmacology*; D001672:Biocompatible Materials; D002118:Calcium; D048271:Chitosan / Q000494:pharmacology*; D002712:Chlorides / Q000494:pharmacology*; D003692:Delayed-Action Preparations / Q000493:pharmacokinetics; D004339:Drug Compounding / Q000379:methods*; D004548:Elasticity / Q000187:drug effects; D005753:Gastric Mucosa / Q000378:metabolism; D006454:Hemoglobins / Q000493:pharmacokinetics; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000378:metabolism; D008863:Microspheres; D010539:Permeability / Q000187:drug effects
chemical_list: D000464:Alginates; D017609:Barium Compounds; D001672:Biocompatible Materials; D002712:Chlorides; D003692:Delayed-Action Preparations; D006454:Hemoglobins; C024986:barium chloride; D048271:Chitosan; D002118:Calcium