Study On The Functional Ploymer Drug-loaded Nano-particles

In order to improve the treatment efficacy and reduce the side effect of 5-fluorouracil (5-Fu), 5-Fu as model drug and the sustained-releaser of targeted 5-Fu-loaded nanopartilce w ere p repared. D rug-loaded ploybutylcyanoacrylate na nocapsules(PACA) was prepared by interfacial polymerization, The resulted poly-compound was determined by the spectra of 1H Nuclear Magnetic Resonance(NMR) and 'H-'H-COSYCCorrelated Specters Copy), and also the reaction mechanism of interfacial polymerization was studied. At the same time, drug-loaded ploybutylcyanoacrylate nanospheres were prepared by emulsion polymerization. In regard to interfacial polymerization and emulsion polymerization, the influence of physicochemical and technical parameters, such as pH of aqueous phase, monomer concentration, oil concentration, type and concentration of surfactants and stabilizer on the result particle size, size distribution of PACA nanoparticles, drug-loading, and encapsulation efficiency were investigated, respectively. Nanoparticles size and surfacial characterization were performed by scanning electron microcopy(SEM). The finding show: that the dispersion of monomer in water, containing 0.5%(weight/volume) monomer and 1.5% Dextrin T-70 as stabilizer and Poloxamer 188 as surfactants, by emulsion polymerization, allows the formation of nanospheres with an average diameter about 200nm, The pH of this solution is around 2 or 3. The 5-Fu-loading nanosphers are very low, and release rapidly from nanopheres, and so it is not suitable for loading 5-Fu. The dispersion of organic phase(monomer/ ethanol=0.1) in water, containing 1.5% Dextrin T-70 as stabilizer and Poloxamer 188 as surfactants, by interfacial polymerization, allows the formation of nanocapsules with an average diameter of 220nm and 35% 5-Fu-loading. The ratio of organic and water is 0.5 and the pH of the solution is around 6. 5-Fu concentration was determined using ultraviolet spectroscopy(UV). The influence of different type of monomer, monomer concentration and drug-loading on in the in vitro drug release characteristics was also investigated. The release data were fitted to the equation (M, =MxKt") to determine the release kinetics. A value of n less than 0.5 has not been shown to correspond to Huigchi release. 5-Fu r elease from PBCAnanocapsules occurs in three phases: burst release, slow release and biodegrade. Through synthesizing experiment, data-fitting and theory-studying, Being small size , 5-Fu-loaded PACA may target to liver, and seem to have significant advantages and important reference value.