Taylor dispersion analysis and release studies of β-carotene-loaded PLGA nanoparticles and liposomes in simulated gastrointestinal fluids.

β-Carotene (βC), a natural carotenoid, is the most important and effective vitamin A precursor, known also for its antioxidant properties. However, its poor water solubility, chemical instability, and low bioavailability limit its effectiveness as an orally delivered functional nutrient. Nanoparticle encapsulation improves βC's bioaccessibility by enhancing its stability and solubility. This study compares two formulations, βC-loaded poly(lactic--glycolic acid) (PLGA) NPs and liposomes before and after exposure to simulated gastrointestinal fluids using various methods such as Taylor dispersion analysis (TDA), cryo-transmission electron microscopy, dynamic light scattering (DLS), and nanoparticle tracking analysis (NTA). TDA, a microfluidic technique, proved more effective than DLS and NTA in determining nanoparticle size in simulated gastrointestinal fluids. This highlights TDA's potential for assessing nanoparticle colloidal stability in simulated gastro-intestinal fluids, crucial for evaluating encapsulated bioactives' bioavailability. High-performance liquid chromatography (HPLC) revealed that PLGA nanoparticles incorporate and preserve βC more effectively during long-term storage compared to liposomes. Adding ascorbic acid significantly reduced degradation in simulated gastrointestinal fluids. Release studies showed that liposomes released 52% of βC after 36 hours, while PLGA nanoparticles released only 9% over 168 hours. These results provide valuable insights for selecting an appropriate βC nanocarrier for oral delivery based on desired release rates.