Bigel based on monoglyceride and hydroxypropyl methylcellulose: preparation, characterization, and application in the release of ferulic acid

BACKGROUND: Bigels based on hydroxypropyl methylcellulose (HPMC)/glycerol monostearate (GMS) were developed as a delivery system for ferulic acid (FA). The effect of the oleogel-to-hydrogel ratio (100:0, 75:25, 50:50, 25:75, 0:100), as well as the order of phase addition, on the physicochemical properties of the bigel and the FA release rate was evaluated. Six formulations (samples S1-S6) were prepared while maintaining a fixed amount of FA in all samples, and FA release was investigated under simulated intestinal conditions (pH 6.8). RESULTS: The results showed that increasing the hydrogel fraction accelerated FA release due to the formation of a more continuous aqueous network, whereas higher oleogel content slowed release by providing a diffusion barrier. The release ratio ranged from 10% to 80%, confirming effective loading of FA in all formulations. The physicochemical properties of the bigels demonstrated that matrix composition plays a critical role in modulating diffusion-controlled release behavior. CONCLUSION: These findings demonstrate that HPMC/GMS bigels represent a promising food-grade delivery system for controlling the intestinal release of FA through compositional design. Although the study was limited to in vitro conditions at a single pH, future work will focus on evaluating release under multiple gastrointestinal conditions to further assess the applicability of these bigel systems for oral delivery of phenolic compounds in food and agricultural products. © 2026 Society of Chemical Industry.