Synthesis, Characterization and Safety Profiling of Eudragit-Based pHResponsive Hydrogels: A Promising Platform for Colonic Delivery of Losartan Potassium

The aim of the present study was to design an efficient delivery system with an anticipated swelling and drug release properties for a prolonged drug release as well as to target colon for various hydrophilic drugs.

For this purpose, the pH-responsive hydrogel comprising a combination of Eudragit and acrylic acid was formed. The hydrogels were characterized for spectral (FTIR), thermal (TGA/DSC), structural (XRD), and morphological (SEM) investigations. Oral tolerability was assessed in rabbits for biocompatibility and oral use of the prepared hydrogels.

The results showed that an increased incorporation of Eudragit and cross-linking agent retorted the swelling, drug loading, and drug release properties at both acid (pH 1.2) and basic pH (pH 6.8 and 7.4) , while acrylic acid presented the inverse results. The oral tolerability and toxicity studies depicted that the developed hydrogels were safe up to 3800 mg/kg body weight and caused no hematological or histopathological changes when compared with the control group.

Therefore, the newly developed formulations presented adequate swelling, drug loading, release behavior, and biocompatibility properties and thus can be used as a promising tool for the colonic delivery of various hydrophilic drugs.