In Vitro Evaluation of a Fluorescent Microemulsion as an Oral Delivery Carrier and its Potential Application in Tracking Bioactive Compounds Label-Free.

In this work, a microemulsion emitting fluorescence was fabricated as a potential oral delivery system for bioactive compounds. In simulated oral administration, the microemulsion was characterized for its microstructure by 1hydrogen-nuclear magnetic resonance (1H-NMR). Results showed that microemulsions not only have good resistance to oral and gastric phases, but also lay a solid foundation for the release of bioactive compounds in the intestine. Fluorescence stability tests showed that microemulsions exhibit a remarkable fluorescence intensity in the digestive environment, indicating feasibility as a label-free delivery carrier. Moreover, in vitro release tests of bioactive compounds confirmed that an α-linolenic acid (ALA)-loaded microemulsion mainly released in the intestine, thereby achieving the aim of controlling the release of bioactive compounds. These results suggest that the synthesized fluorescent microemulsion, combining the favorable features of nontoxicity, antidigestive stability, remarkable fluorescence intensity, and controllable release, can be regarded as a promising label-free delivery carrier for oral administration.