title: Development of core-shell microcapsules by a novel supercritical CO2 process.
abstract: 5-fluorouracil-SiO(2)-poly(L-lactide) (5-Fu-SiO(2)-PLLA) microcapsules were prepared in a novel process of solution-enhanced dispersion by supercritical CO(2) (SEDS). The SiO(2) nanoparticles were loaded with 5-Fu by adsorption at the first place, then the 5-Fu-SiO(2) nanoparticles were coated with PLLA by a modified SEDS process. The resulted microcapsules were characterized by scanning electron microscope (SEM), laser diffraction particle size analyzer, Fourier transform infrared spectrometer (FTIR) and thermogravimeter-differential scanning calorimeter (TG-DSC). The drug load, encapsulation efficiency and drug release profiles were also determined. The resulted microcapsules exhibited a rather spherical shape, smooth surface, and a narrow particle size distribution with a mean particle size of 536 nm. The drug load and encapsulation efficiency of the samples were 0.18% and 80.53%, respectively, 25.05% of 5-Fu was released in the first half hour, then drug released in a sustained process, which was much slower than that of without coated by PLLA. The results indicated that the modified SEDS process could be used to produce drug-polymer microcapsules with a core-shell structure, high encapsulation efficiency and sustained drug release effect.
authors.affiliation: Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
authors.forename: Ai-Zheng
authors.initials: AZ
authors.lastname: Chen
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.forename: Dong
authors.initials: D
authors.lastname: Chen
authors.forename: Jun-Yan
authors.initials: JY
authors.lastname: Hu
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry; D002214:Capsules / Q000138:chemical synthesis* / Q000737:chemistry; D002245:Carbon Dioxide; D003692:Delayed-Action Preparations; D004339:Drug Compounding / Q000295:instrumentation / Q000379:methods; D005472:Fluorouracil / Q000008:administration & dosage; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D001672:Biocompatible Materials; D002214:Capsules; D003692:Delayed-Action Preparations; D011091:Polyesters; D002245:Carbon Dioxide; C033616:poly(lactide); D012822:Silicon Dioxide; D005472:Fluorouracil