title: Composite chitosan hydrogels for extended release of hydrophobic drugs.
abstract: A composite chitosan hydrogel durable in physiological conditions intended for sustained release of hydrophobic drugs was investigated. The design is based on chitosan crosslinked with genipin with embedded biocompatible non-ionic microemulsion (ME). A prolonged release period of 48 h in water, and of 24h in phosphate buffer saline (PBS) of pH 7.4 was demonstrated for Nile red and curcumin. The differences in release patterns in water and PBS were attributed to distinct dissimilarities in the swelling behaviors; in water, the hydrogels swell enormously, while in PBS they expel water and shrink. The release mechanism dominating this system is complex due to intermolecular bonding between the oil droplets and the polymeric network, as confirmed by Fourier transform infrared spectroscopy (FTIR) experiments. This is the first time that oil in water microemulsions were introduced into a chitosan hydrogels for the creation of a hydrophobic drug delivery system.
authors.affiliation: The Russell Berrie Nanotechnology Institute, Technion - Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Keren
authors.initials: K
authors.lastname: Delmar
authors.affiliation: The Russell Berrie Nanotechnology Institute, Technion - Israel Institute of Technology, Haifa 32000, Israel; Department of Chemical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel. Electronic address: bianco@tx.technion.ac.il.
authors.forename: Havazelet
authors.initials: H
authors.lastname: Bianco-Peled
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D003474:Curcumin / Q000737:chemistry; D004337:Drug Carriers / Q000737:chemistry*; D065546:Drug Liberation; D020100:Hydrogels / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D010078:Oxazines / Q000737:chemistry
chemical_list: D004337:Drug Carriers; D020100:Hydrogels; D010078:Oxazines; D048271:Chitosan; D003474:Curcumin; C044808:nile red
keywords: Chitosan; Drug delivery; Hydrogel; Hydrophobic drugs; Microemulsion