Anomalous dissolution property enhancement of naringenin from spray-dried particles with α-glucosylhesperidin

Spray-dried particles were prepared with α-glucosyl hesperidin (Hsp-G), a hesperidin derivative with enhanced water solubility, to improve the solubility profile of naringenin (NRG). Naringenin was used as a model hydrophobic polyphenol. The spray-dried sample of NRG in the presence of Hsp-G formed 3–4 μm spherical particles. Those particles showed a halo pattern in powder X-ray diffractometry, indicating the amorphous state of NRG in the solid dispersion with Hsp-G. Interestingly, the obtained powders dissolved immediately into the aqueous media and demonstrated dramatically high apparent solubility, over 60-fold greater than NRG crystals, when the loading ratio of NRG/Hsp-G was 1/20. The apparent solubility of NRG increased in proportion to the amount of Hsp-G loaded (R2 > 0.99). These results suggested that a specific molecular interaction, a micelle-like structure in which NRG was incorporated with Hsp-G molecules, was formed in spray-dried particles, resulting in the anomalous enhancement in the solubility of NRG.