Combining porous starch and polyoxyethylene hydrogenated castor oil RH40 to enhance the solubility, stability, and bioavailability of bisdemethoxycurcumin

Bisdemethoxycurcumin (BDC) is an important ingredient derived from the food spice turmeric. Although BDC exhibits various pharmacological effects, it is characterized by poor water solubility and limited stability under light. Considering that the high specific surface area of porous starch (PS) renders it an ideal carrier for the encapsulation of active compounds, and polyoxyethylene‑hydrogenated castor oil RH40 (RH40) is an effective solubilizer for BDC, the current study optimized the PS/RH40/BDC formulation to combine these advantages. Consequently, a PS/RH40/BDC ratio of 10:3:1 was identified as optimal (RH-PS/BDC). Characterization using scanning electron microscopy, X-ray diffractometry, Fourier-transform infrared spectroscopy, Brunauer–Emmett–Teller analysis, and stability testing indicated that BDC was amorphously encapsulated within the RH-PS system, thereby leading to enhanced stability and solubility. Furthermore, cellular uptake experiments revealed a significant increase of RH-PS/BDC. In terms of the enhancement mechanism, RH40 can reduce cell membrane fluidity and open tight junctions between intestinal epithelial cells, thereby facilitating BDC absorption. In vivo pharmacodynamic analysis confirmed that RH-PS/BDC effectively inhibited LPS-induced cerebral neuritis. Overall, this study demonstrates the role of PS in combination with RH40 in enhancing the stability and bioavailability of BDC. This simple and efficient preparation strategy is promising for future research and product development.