Preparation, characterization and in vitro activities evaluation of curcumin based microspheres for azathioprine oral delivery

The main target of this study was the preparation, characterization and in vitro activities evaluation of microspheres curcumin-based able to incorporate azathioprine, useful for psoriasis treatment. Curcumin was derivatized with acryloyl chloride in order to introduce polymerizable groups in its structure. The obtained polymerizable drug was characterized by Fourier transform infrared (FT-IR), to confirm ester linkages, and by 1H-NMR, to establish the functionalization degree. The ability of curcumin derivative to inhibit cell proliferation, in human breast cancer cells, gave an IC50 value for viability of 20 μM. Acrylated curcumin also showed a strong antioxidant activity against lipid peroxidation induced in rat liver microsomal membranes. Then, spherical microparticles, based on curcumin derivative, were prepared by suspension radical copolymerization. The obtained microparticles were characterized by FT-IR spectroscopy, dimensional and morphological analysis. Particle size investigation revealed a mean diameter of around 5.8 μm. Microspheres showed a very good swelling behavior in simulating intestinal fluids. Their azathioprine loading efficiency, determined by spectophotometric analysis was equal to 80%. Release profile of azathioprine showed an initial dot of around 60% and a further release for 24 h.