title: Designing a biocompatible hydrogel for the delivery of mesalamine.
abstract: A new design for nanocomposite hydrogels based on cross-linked chitosan for the delivery of mesalamine is presented. To enhance drug loading in chitosan, the mineral montmorillonite was incorporated into the matrix. The exfoliated silica montmorillonite nanosheets form interactions with both chitosan and mesalamine, which affect the hydrogel's drug release mechanism and swelling properties. The impact of montmorillonite and glutaraldehyde concentrations on the hydrogel properties was investigated. In vitro drug-release studies detected slower release over short times when montmorillonite was introduced into the matrix. This study is the first to evaluate the influence of pH during mixing and on mixing duration. It was shown that lowering the pH during mixing delayed the release since the positively charged drug was better introduced between the montmorillonite layers, as confirmed by differential scanning calorimetry (DSC) and fourier transform infrared spectroscopy (FTIR) analysis. All hydrogels showed prolonged sustained release of mesalamine over 24h in simulated colonic fluid (pH 7.4). When modeled, the mesalamine release profile suggests a complex release mechanism, involving adsorption of the drug to the montmorillonite and its diffusion. The results imply that chitosan-montmorillonite hydrogels can serve as potential drug carriers for controlled-release applications.
authors.affiliation: Department of Chemical Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Lena
authors.initials: L
authors.lastname: Neufeld
authors.affiliation: Department of Chemical Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Havazelet
authors.initials: H
authors.lastname: Bianco-Peled
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage*; D001546:Bentonite; D001672:Biocompatible Materials; D002626:Chemistry, Pharmaceutical; D003432:Cross-Linking Reagents; D004337:Drug Carriers; D016503:Drug Delivery Systems; D015195:Drug Design; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D019804:Mesalamine / Q000008:administration & dosage*; D008970:Molecular Weight; D049329:Nanostructures; D010316:Particle Size
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D004337:Drug Carriers; D020100:Hydrogels; D001546:Bentonite; D019804:Mesalamine
keywords: Chitosan; Hydrogels; Mesalamine (5-Aminosalicylic acid (5-ASA)); Montmorillonite