Engineering Robust, Porous Guar Gum Hydrogels by One-Step Mild Synthesis: Impact of Porogen Choice on Rheology and...

This study introduces a single-step method to synthesize guar gum-based interpenetrating polymer network (IPN) hydrogels, achieving simultaneous Diels-Alder crosslinking and amoxicillin (AMOX) encapsulation under mild conditions. To evaluate the influence of porogen addition on IPN structure, drug loading and release, twenty-one formulations were developed, including AMOX loading (25% or 40% w/w relative to the polymer) and biocompatible porogens incorporation [polyethylene glycol (PEG) or sucrose at 5%, 10%, or 50% w/w]. All crosslinked IPN hydrogels formed robust gels, unlike non-crosslinked controls. Porogen choice strongly influenced hydrogel performance: PEG quadrupled the swelling index while enhancing storage modulus (up to 10,054 Pa) and complex viscosity (up to 1302 Pa·s), whereas high sucrose concentrations produced soft, ductile networks with critical strains above 20% and swelling indices up to 1895%. All hydrogels released AMOX at levels above MIC₅₀ for H. pylori. PEG-based IPN provided superior drug delivery profiles, with extended AMOX release (t₅₀ up to 15.5 h at pH 5.0), while sucrose-rich matrices exhibited faster burst release and disintegration. Single-step (pre-loading) AMOX during synthesis improved release control compared to post-loading. These findings highlight the potential of one-pot IPN synthesis with porogen modulation offering a promising gastroretentive platforms for sustained AMOX delivery against H. pylori.