sustained release of naproxen in a new kind delivery system of carbon nanotubes hydrogel

in this paper, carbon nanotubes (cnts) were added into chitosan (cs) hydrogels in the form of chitosan modified cnts (cs-cnts) composites to prepare carbon nanotubes hydrogels (cnts-gel). the products, named cs-mwcnts, were characterized by scanning electron microscope (sem) and fourier transform infrared (ftir) spectroscopy. swelling properties and effect of ph on controlled release performance of the two kinds of hydrogels, cnts-gel and pure chitosan hydrogels without cnts (gel), were investigated respectively. the results showed that cnts-gel possess better controlled release performance than gel. the releasing equilibrium time of cnts-gel was longer than that of gel in both ph = w7.4 and ph=1.2 conditions, although the release ratios of the model drug are similar in the same ph buffer solutions. it is found that release kinetics is better fitted ritger-peppas empirical model indicating a fick-diffusion process in ph = 1.2, while in ph = 7.4 it was non-fick diffusion involving surface diffusion and corrosion diffusion processes.