Synthesis, Characterization and In Vitro Drug Release of Melphalan Magnetic Microspheres

A new method of reversible association of melphalan (MEL) to magnetic Fe3O4 nanoparticles preparing MEL magnetic microspheres was developed for magnetically targeted chemotherapy. The efficacy of this approach was evaluated in terms of encapsulation efficiency (EE), drug loading content (DLC), delivery properties and cytotoxicity in vitro. Magnetic Fe3O4 nanoparticles were synthesized by co-precipitation methods and characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and magnetization measurements. The MEL magnetic microspheres were obtained through emulsion cross-linking method and characterized by FTIR, magnetization measurements and scan electron microscopy (SEM). The EE and DLC were determined using a Spectro Vision DB-18805 spectrophotometer. The MEL magnetic microspheres showed good EE values, between 60.6% and 75.6%, as well as good DLC values, between 16.7% and 32.2%, and the magnetic properties were not significantly affected by incorporation of the drug. The in vitro drug release study was carried out in phosphate buffer solution (PBS), simulating physiologic body fluid conditions at 37o C with pH = 7.4. The release profiles showed an initial fast release rate, which decreased as time progressed; about 60% of the drug was released in the first 4 h, and about 78.23 % had been released after 24 h. The results indicated that the prepared magnetic microspheres may be useful for potential applications of MEL for magnetically targeted chemotherapy.