title: Hydroxypropyl chitosan bearing beta-cyclodextrin cavities: synthesis and slow release of its inclusion complex with a model hydrophobic drug.
abstract: Hydroxypropyl chitosan-graft-carboxymethyl beta-cyclodextrin (HPCH-g-CM beta-CD) was synthesized by grafting CM beta-CD onto HPCH using water soluble 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) as the condensing agent. Due to the presence of hydrophobic beta-CD rings onto the HPCH backbone, this polymer can be used as a matrix for controlled drug release. The adsorption of a hydrophobic model drug, ketoprofen, by HPCH-g-CM beta-CD microparticles (using tripolyphosphate as an ionic crosslinking agent) fitted well in the Langmuir isotherm equation. The drug dissolution profile showed that HPCH-g-CM beta-CD microparticles provided a slower release of the entrapped ketoprofen than chitosan, and the release behavior was influenced by the pH value of the medium. These results suggest that beta-CD grafted with chitosan derivatives may become a potential biodegradable delivery system to control the release of hydrophobic drugs with pH-responsive capability.
authors.affiliation: 3B's Research Group-Biomaterials, Biodegradables and Biomimetics, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal.
authors.forename: Mani
authors.initials: M
authors.lastname: Prabaharan
authors.forename: João F
authors.initials: JF
authors.lastname: Mano
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage* / Q000493:pharmacokinetics; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D048271:Chitosan / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000138:chemical synthesis / Q000493:pharmacokinetics; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007660:Ketoprofen / Q000008:administration & dosage* / Q000493:pharmacokinetics; D010316:Particle Size; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D003692:Delayed-Action Preparations; D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin; D048271:Chitosan; D007660:Ketoprofen