Comparative Evaluation of Release Profiles from Hydrogel, Oleogel, and Bigel Systems Containing Model...

This study presents a comparative evaluation of hydrogel, Oleogel, and bigel formulations incorporating model radiopharmaceuticals[99 mTc]-Tc-DTPA (hydrophilic) and [99 mTc]-Tc-HMPAO (lipophilic)for potential buccal drug delivery applications. The gels were characterized in terms of rheological behavior, mechanical properties, and mucoadhesive strength to assess their suitability for mucosal administration. In vitro permeation studies using Franz diffusion cells with synthetic membranes were performed to evaluate the release profiles of the radiolabeled compounds. The findings demonstrated that bigel formulations exhibited the most favorable mechanical and viscoelastic properties, superior release for both hydrophilic and lipophilic agents, and enhanced mucoadhesive performance compared to hydrogel and Oleogel systems. Oleogels, while showing good adhesiveness, were less effective in drug release, particularly for hydrophilic compounds. Hydrogels displayed high mucoadhesion but limited release for lipophilic drugs. The biphasic nature of bigels provided a versatile matrix capable of optimizing the delivery of diverse radiopharmaceuticals through the buccal route.