Phospholipid/hydroxypropyl-β-cyclodextrin supramolecular complexes are promising candidates for efficient oral delivery of curcuminoids

Curcumin (Cur) and demethoxycurcumin (Dcur) are two natural analogues of phenol extracted from turmeric, possessing various pharmacological properties. However, their therapeutic potentials are substantially limited by their rather poor aqueous solubility and bioavailability. Herein, novel soluble supramolecular complexes of the two curcuminoids were firstly prepared by integrating phospholipid (PC) compound technology and a hydroxypropyl-beta-cyclodextrin (HP beta CD) inclusion technique to enhance the bioavailability of the curcuminoids. The PC-HP beta CD supramolecular complexes were demonstrated to show improved solubility, augmented drug release, enhanced in situ gastrointestinal absorption, and increased oral bioavailability. The significantly increased bioavailability might be attribute to the appropriate particle sizes (< 200 nm), the near-neutral suface charges as well as the additional effects of PC and HP beta CD. Overall, the PC-HP beta CD supramolecular complexes may be considered as promising candidates for the efficient oral delivery of the curcuminoids; moreover, they are inexpensive, simple to prepare, and have good market prospects. Interestingly, the two natural analogues were found to be different in their in vivo bioavailability with or without supramolecular complexing, probably owing to the difference in the phenylmethoxy group. Therefore, Dcur may have a broader prospect in the pharmaceutical industry, based on its remarkable improvement in bioavailability and reported physiological activity.