Physicochemical Properties and Release Study of Antimetabolite-Incorporated Stearoyl Chitosan

Stearoyl chitosan (SC), derived from the acylation of chitosan, contributes to the efficiency of drug delivery systems because of its structure, which accommodates the drug in a particle. Nonetheless, its role in chemotherapy has been largely unexplored. The present study involves the synthesis of stearoyl chitosan through the reaction of depolymerized chitosan with stearoyl chloride under mild reaction conditions. The resulting compound was subjected to structural analysis utilizing Fourier-transform infrared (FTIR) spectroscopy, 1H NMR, and X-ray diffraction (XRD) spectroscopy. The dispersion of SC molecules in phosphate-buffered saline (PBS) forms SC nanoparticles. The best dispersion of SC in the solution was achieved at a 1:60 chitosan-to-stearoyl chloride weight ratio. Three antimetabolite drugs, methotrexate, pemetrexed, and raltitrexed, were selected to examine the loading efficacy of SC. Pemetrexed had the highest drug-loading value of 36.8% among the three antimetabolites incorporated into SC, along with an encapsulation efficiency of 85.1%. The size of SC loaded with antimetabolites ranged from 225 to 369 nm, and their spherical form was verified via a transmission electron microscope. The in vitro release study showed that SC demonstrated controlled drug release, suggesting that SC nanoparticles have significant promise as a delivery strategy for chemotherapy.