A sustained release of model drug from a novel polyacrylic acid-polyaluminium chloride superabsorbent

A new kind of drug loaded superabsorbent polymer was prepared and the properties of drug delivery performance are reported in the current study. The superabsorbent polymer was prepared via a process in which polyacrylic acid (PAA) was cross-linked via complex formation with polyaluminium chloride (PAC) through AlCl ₃ hydrolysis under alkaline conditions followed by freeze drying. The drugs were loaded into the network structure of the superabsorbent during the complex formation of cross-linking process. The new drug loaded superabsorbents were prepared aiming to overcome the drawbacks of those prepared via conventional method. The loading as well as the sustained release of the model drug acetaminophen (AMP) using the prepared superabsorbent has been studied by UV-absorption spectroscopy, and compared with superabsorbent prepared via conventional free radical polymeri-zation method. It was found that the AMP loaded before complex formation of cross-linking process and showed a much better loading performance and drugs sustained release properties compared to the product with which AMP was added during the process of complex formation of cross-linking process. The drug release mechanism has been analyzed for the polymers with different cross-linking densities via numerical simulation based on different kinetic models as well as the Ritger-Peppas equation. At the same time, it is found that the AMP release rate at pH 4 is initially greater than that at pH 10 and release rate increases as temperature is increased.