title: Sustained release of 5-FU from Poloxamer gels interpenetrated by crosslinking chitosan network.
abstract: This study investigates in vitro the drug delivery characteristics of new thermo-sensitive gels, P-CS/GA gels, in which a chitosan (CS) network is crosslinked with various concentrations of glutaraldehyde (GA) that interpenetrates Poloxamer (P) gels. The results indicate that the swelling ratios of all P-CS/GA gels are markedly superior to those of non-swelling P and P-CS gels. For example, P-CS/GA (0.1 wt.%) gels have swelling ratios of 13.2+/-1.0, which are maintained for approximately 18 h in water at 37 degrees C. In vitro releases of 5-FU from P-CS/GA (0.1 wt.%) gels had significantly lower initial burst release (P<0.01) and lasted much longer than those from gels without a CS network. For example, the duration of release of 5-FU was in a significantly sustained manner for up to 52 h, which was about 10 times or longer than the period of delivery using P or P-CS gels. The release of drugs from gels with an interpenetrating CS network could be modeled by Fickian diffusion; the characteristic constant 'k' of drug-gel systems decreased as increasing GA concentrations in the P-CS/GA gels, and increasing the viscosities of the P, P-CS and P-CS/GA solutions.
authors: Department of Chemical and Material Engineering, National Yunlin University of Science and Technology, Dou-Liu, Yunlin, Taiwan. twchung@yuntech.edu.tw
authors: Tze-Wen
authors: TW
authors: Chung
authors: Shyr-Yi
authors: SY
authors: Lin
authors: Der-Zen
authors: DZ
authors: Liu
authors: Yu-Chang
authors: YC
authors: Tyan
authors: Juin-Sen
authors: JS
authors: Yang
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D048271:Chitosan / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D003692:Delayed-Action Preparations; D004058:Diffusion; D004337:Drug Carriers; D004339:Drug Compounding; D005472:Fluorouracil / Q000737:chemistry*; D005782:Gels; D005976:Glutaral / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D008968:Molecular Conformation; D020442:Poloxamer / Q000737:chemistry*; D012995:Solubility; D013696:Temperature; D014783:Viscosity
chemical_list: D000964:Antimetabolites, Antineoplastic; D003432:Cross-Linking Reagents; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D005782:Gels; D020442:Poloxamer; D048271:Chitosan; D005976:Glutaral; D005472:Fluorouracil