Spray-dried curcumin nanoemulsion: A new road to improvement of oral bioavailability of curcumin.

In this study a new soluble solid curcumin nanoemulsion powder was prepared using spray-drying technology to improve the solubility and bioavailability of curcumin. The liquid nanoemulsion consisted of curcumin, Capryol 90, Transcutol P, and Cremophor RH40. The solid nanoemulsion was prepared by spray-drying the liquid nanoemulsion in laboratory spray dryer, using lactose as solid carrier. The in vitro release from powder formulation was 97.6% within 15 min while the release from the curcumin crystalline was about 10%. An oral pharmacokinetic study was conducted in rats and the relative bioavailability of spray-dried curcumin powder significantly increased compared with that of curcumin crystalline. The C value of solid curcumin nanoemulsion powder was 5.5-fold greater than the value of the curcumin crystalline in aqueous suspension. The absorption mechanism of the spray-dried curcumin powders was discussed. The results indicate that spray-drying in combination with nanoemulsion was a powerful methodology for improving the dissolution rate and oral bioavailability of curcumin.