Complex of chitosan pectin and clay as diclofenac carrier

The preparation of a new drug delivery system (DDS) based on the combination of two natural polymers chitosan (CS) and high-esterified pectin (HEP) and beidellite (Bd) was proposed. Diclofenac sodium was chosen as model drug and was loaded in the nanocomposite by means of intercalation solution technique. The samples were characterized by X-ray diffraction, Thermal analysis, Infrared spectroscopy and high resolution transmission electron microscopy coupled with energy dispersive X-Ray analysis. Drug loading capacity and encapsulation efficiency of the clay polymer nanocomposite was quantified. UV–Vis spectroscopy (276 nm) was used as the drug quantification technique throughout the whole study. In vitro drug release profile in simulated intestinal fluid was also evaluated. Results demonstrated the formation of diclofenac polymorph during the drug loading process, thus obtaining a new crystal form of the drug possessing different physico-chemical properties with respect to the diclofenac sodium salt form. Moreover, the in vitro release study showed that the bionanocomposite elaborated could form a network aiming for a modified release of diclofenac. Consequently, Na-Bd/CS/HEP nanocomposite proved to be a promising formulation to control anionic drug release process.