Document Type: Research Paper
Department of Chemistry, Karaj Branch, Islamic Azad University, P.O. Box 31485‑313, Karaj, Iran
A descriptive study of isothermal kinetics of diclofenac release from chitosan-g-acrylic acid (Chit-AA) hydrogel and chitosan-g-(acrylic acid-co-[2-(acryloyloxy)ethyl]trimethylammonium chloride) (Chit-AA-AETM) hydrogel was carried out. Isothermal kinetic curves for diclofenac release from both hydrogels in distilled water at various temperatures of 20-42°C were studied. The fit method of the famous model was used to determine the kinetic models of both the drug release process and the external solvent absorption onto the hydrogel. Based on the fixed dependencies of kinetic parameters (LnA, Ea) on the amount of abandoned diclofenac (α) in the presence of compensatory effect, the function of the new molecular mechanism of a drug transfer process was investigated. According to that mechanism, drug release is considered as an isolation of the drug from the active separation centers of various hydrogels with different energies.