Synthesis and Evaluation of pH and Thermosensitive Pectin-Based Superabsorbent Hydrogel for Oral Drug Delivery Systems

The purpose of this study was to produce intelligent pectin-based superabsorbent polymers (SAP) to be used as pH- and thermosensitive carriers for the controlled delivery of non-steroidal anti-inflammatory drugs (NSAIDs). The superabsorbent formation was confirmed by Fourier transform infrared spectroscopic (FT-IR) and scanning electron microscopy (SEM). The effects of pH, ionic strength, temperature, porosity, particle size and levels of loaded drug on drug release profile in various surrounding media were investigated. Each sample was well characterized through swelling studies. The molecular weight between crosslinks ((M) over barC), crosslinking density (V-e) polymer-solvent interaction parameter (chi), and the shear modulus of the superabsorbents (G) were calculated. The results revealed that the release profiles of IBU from the superabsorbent polymer were low (lower than 14%) in simulated gastric fluid (SGF, pH 1.2) over 3 h, but nearly all of the initial drug content (more than 79%) was released in simulated intestinal fluid (SIF, pH 7.4) within 6 h after changing media. Overall the results demonstrated that biodegradable superabsorbents could successfully deliver a drug to the intestine without losing the drug in the stomach, and could be potential candidates for an orally administrated drug delivery system.