A multiple emulsion method for loading 5-fluorouracil into a magnetite-loaded nanocapsule: a physicochemical investigation

The preparation of 5-fluorouracil (5-FU) loaded poly(lactic-co-glycolic acid) (PLGA) biodegradable nanocapsules containing magnetite nanoparticles was studied through the modified multiple emulsion solvent evaporation method for magnetically controlled delivery of anticancer drugs. The morphology and size distribution of the prepared magnetite/PLGA nanocapsules were investigated by transmission and scanning electron microscopy. The micrographs showed that the magnetic nanocapsules were almost spherical in shape and their mean diameter was in the nanometer range with a narrow size distribution. Fourier transform infrared and ultraviolet–visible spectroscopy confirmed incorporation of 5-FU molecules into the PLGA matrix. The magnetite content was assessed by thermogravimetric and magnetometry analysis and the results showed a magnetite content of 35 wt% with high magnetic responsivity. Magnetometry measurements showed superparamagnetic properties of the magnetic nanocapsules with a saturation magnetization of 13.7 emu g−1. Such biodegradable magnetic nanocapsules could be considered as an appropriate choice for drug targeting. Furthermore, the influence of some important processing parameters such as PLGA concentration, initial loading of 5-FU and poly(vinyl alcohol) concentration on drug content, encapsulation efficiency and in vitro drug release kinetics was investigated and optimized. The drug content and encapsulation efficiency of the magnetic nanocapsules were 4–7 wt% and 60%–80%, respectively, and the nanocapsules demonstrated controlled release of 5-FU at 37 °C in a buffer solution. All samples exhibited a burst release at the initial stage and this burst release showed its close dependence on the formulation parameters. Copyright © 2012 Society of Chemical Industry