Theaflavins loaded niosomes: characterization and in vivo biodistribution in Wistar albino rats

Theaflavins (TFs), bioactive compounds present in black tea manufactured from leaves of Camellia sinensis, have potent health benefits. TFs are unstable and have low bioavailability due to their low solubility in water. In the present study, we have attempted to encapsulate TFs into niosomes to enhance stability, bioavailability, and therapeutic applications. This study explored the potential of niosomes loaded with theaflavins (TFs-L-NS), a formulation designed to overcome the limitations of the natural compound theaflavins (TFs). TFs-L-NS was successfully developed with desirable characteristics including nanosize (111.5 nm), surface charge (-95.5 mV), encapsulation of TFs (78%), and in vitro release profile of TFs from TFs-L-NS (47%) with slow and sustained release. SEM, TEM, and fluorescent microscopic studies revealed that TFs-L-NS has a spherical form and a smooth surface. A two-month stability study indicated good stability of TFs-L-NS. In vivo studies demonstrated the distribution of DiR-labeled TFs-L-NS throughout the body and vital organs in a rat model.