title: Chitosan/polyethylene glycol beads crosslinked with tripolyphosphate and glutaraldehyde for gastrointestinal drug delivery.
abstract: This study reports on the preparation of chitosan (CS)/polyethylene glycol (PEG) hydrogel beads using sodium diclofenac (DFNa) as a model drug. Following the optimization of the polymer to drug ratio, the chitosan beads were modified by ionic crosslinking with sodium tripolyphosphate (TPP). The CS/PEG/DFNa beads obtained from a (w/w/w) ratio of 1/0.5/0.5 with crosslinking in 10% (w/v) TPP at pH 6.0 for 30 min yielded excellent DFNa encapsulation levels with over 90% loading efficiency. The dissolution profile of DFNa from CS/PEG/DFNa beads demonstrated that this formulation was able to maintain a prolonged drug release for approximately 8 h. Among the formulations tested, the CS/PEG/DFNa (1/0.5/1 (w/w/w)) beads crosslinked with a combination of TPP (10% (w/v) for 30 min) and glutaraldehyde (GD) (5% (w/v)) were able to provide minimal DFNa release in the gastric and duodenal simulated fluids (pH 1.2 and 6.8, respectively) allowing for a principally gradual drug release over 24 h in the intestinal (jejunum and ileum) simulated fluid (pH 7.4). Thus, overall the CS/PEG beads crosslinked with TPP and GD look to be a promising and novel alternative gastrointestinal drug release system.
authors.affiliation: Program of Petrochemistry and Polymer Sciences, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
authors.forename: Thawachinee
authors.initials: T
authors.lastname: Buranachai
authors.forename: Nalena
authors.initials: N
authors.lastname: Praphairaksit
authors.forename: Nongnuj
authors.initials: N
authors.lastname: Muangsin
mesh_terms: D000818:Animals; D048271:Chitosan / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D003692:Delayed-Action Preparations / Q000008:administration & dosage* / Q000737:chemistry; D004058:Diffusion; D005765:Gastrointestinal Agents / Q000008:administration & dosage / Q000737:chemistry*; D005766:Gastrointestinal Contents / Q000737:chemistry; D005976:Glutaral / Q000737:chemistry*; D006801:Humans; D008863:Microspheres; D011092:Polyethylene Glycols / Q000737:chemistry*; D011122:Polyphosphates / Q000737:chemistry*
chemical_list: D003432:Cross-Linking Reagents; D003692:Delayed-Action Preparations; D005765:Gastrointestinal Agents; D011122:Polyphosphates; D011092:Polyethylene Glycols; D048271:Chitosan; C005692:triphosphoric acid; D005976:Glutaral