Oral administration is the most preferred route for drug and bioactive delivery, though it raises great challenges due to the involvement of the gastro-intestine system and limited bioavailability. In this research, a new class of gelled oil-based emulsion with long-term stability and high gastrointestinal stability was successfully developed using phytosterols. The microstructure of phytosterols oleogel is based on a three-dimensional fiber network, which entraps both oil and dispersed hydrophobic molecules. The behavior under simulated gastro-intestinal conditions and changes in particle size, zeta potential and morphology were assessed while in vitro lipid hydrolysis and molecular release were measured. Gastro-intestinal digestion tests revealed that unstructured emulsions exhibit higher probability for particle coalescence compared to oleogel-based emulsions. The extent of lipid digestion was correlated to the particle size and mechanical strength where higher phytosterol concentration led to stronger network that served as a physical barrier that hinders lipase access to the oil. However, the total extent of digestion increased with decreasing particle diameter due to the overall increase in oil-water interface which promote lipase activity. Moreover, the results show the formation of smaller mixed micelles during the lipolysis process when the particles were prepared using higher phytosterol concentration implying on the ability to control micelle size during digestion and appreciable increase in the ꞵ-carotene bioaccessibility was observed.
Overall, the results demonstrated that combination of solid and liquid lipid components offers mechanical protection and molecular micellization ability during digestion which can be utilized as effective encapsulation systems for hydrophobic molecules with controllable release.
- Areen Ashkar, Alejandro Sosnik, and Maya Davidovich-Pinhas “Structured edible lipid-based particle systems for oral drug-delivery” Biotechnology Advances 54, 107789 (2022).