Synthesis, characterization and kinetics of sustained pantoprazole release studies of interpenetrated poly(acrylic acid)-chitosan-bentonite hydrogels for drug delivery systems

Clays are widely used in controlled drug delivery systems due to their strong adsorption properties and natural origin. In this study, a drug carrier was prepared using chitosan, a natural polymer, mixed with bentonite clay. Then, poly(acrylic acid) was added to improve its swelling properties. Pantoprazole was chosen as the model drug. The swelling properties of the prepared samples were investigated at two different temperatures: 25 and 37 °C. The prepared samples were examined by Fourier-transform infrared spectroscopy and scanning electron microscopy. The controlled release of the pantoprazole from the drug carriers indicated that the release of the pantoprazole is temperature-sensitive. In order to study the effect of bentonite on the drug carrier system, drug release was also investigated in the samples without adding clay. It was observed that the drug release profiles of the prepared sample containing bentonite fitted better than the sample without clay. The release kinetics analysis showed that the first-order and the Korsmeyer-Peppas models fit the best, and that pantoprazole was transported via Fickian diffusion. The prepared samples showed the capability of pantoprazole loading and, thus, its possibility to be used in drug delivery systems.