title: Estimation of 5-fluorouracil-loaded ethylene-vinyl acetate stent coating based on percolation thresholds.
abstract: The drug percolation thresholds of 5-fluorouracil-loaded ethylene-vinyl acetate stent coatings were estimated to characterize their drug release behavior and mechanical properties. The stent coatings were prepared using 5-fluorouracil (5-FU) as antitumor drug and ethylene-vinyl acetate (EVA) as matrix forming material in different ratios. In vitro release assays were carried out exposing only one side of coating to pH 6.5 PBS. Based on the release profiles, the drug percolation thresholds were estimated as 0.21 of total porosity (corresponding to ca. 32%, w/w of the drug), which is in approximately agreement with the atomic force microscopy (AFM) result. Based on the coating tensible break strength and tear break strength data, the mechanical percolation thresholds of drug were obtained as 39.7+/-0.3 and 37.5+/-1.4% (w/w) of drug content, respectively.
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, 800th Dong-chuan Road, Shanghai 200240, China.
authors.forename: Qing-hai
authors.initials: QH
authors.lastname: Guo
authors.forename: Sheng-rong
authors.initials: SR
authors.lastname: Guo
authors.forename: Zhong-min
authors.initials: ZM
authors.lastname: Wang
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D020099:Coated Materials, Biocompatible; D004058:Diffusion; D004337:Drug Carriers; D005472:Fluorouracil / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D008956:Models, Chemical; D015233:Models, Statistical; D011145:Polyvinyls / Q000737:chemistry*; D016062:Porosity; D012995:Solubility; D015607:Stents; D013314:Stress, Mechanical; D013718:Tensile Strength; D013997:Time Factors
chemical_list: D000964:Antimetabolites, Antineoplastic; D020099:Coated Materials, Biocompatible; D004337:Drug Carriers; D011145:Polyvinyls; C016438:ethylenevinylacetate copolymer; D005472:Fluorouracil