Synthesis, Characterization and Drug Delivery Profile of Magnetic PLGA-PEG-PLGA/Maghemite Nanocomposite

The antibiotic cotrimoxazole was associated to the multi-block copolymer containing poly(D, L-lactic-glycolic acid) (PLGA) and poly(ethylene glycol) (PEG) segments, PLGA-PEG-PLGA, aiming to reach a controlled drug release system. Block copolymer was synthesized via polycondensation of lactic acid and glycolic acid with PEG in situ. In turn, maghemite was synthesized through the co-precipitation method. The drug cotrimoxazole was inserted in the composite through melting mixing method. Several techniques were used to characterize the materials. The materials were characterized by Nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and magnetic force, this last according to the methodology developed by our group. In addition, dissolution profile was studied. These dissolution tests were performed with and without magnetic field, aiming to study the influence of the magnetic field on the dissolution profile. The dissolution was monitored and quantified using the ultraviolet-visible spectrophotometry (UV-Vis), following the USP method for cotrimoxazole tablets. Results demonstrated that nanocomposites presented a good magnetic force, able to keep the magnetic composite trapped in a specific place or tissue. Furthermore, in the presence of a magnetic field, the magnetic nanoparticles were able to perform a magnetic constriction of the material, making the drug release faster than in the absence of the magnetic field. This phenomenon may be useful to perform a fine tuning of the system, allowing the easier adjust of the speed and amount of released drug, useful to improve medical treatments and even the welfare of the patients.