Comparative bioavailability of curcuminoids from a water-dispersible high curcuminoid turmeric extract against a generic turmeric extract: a randomized, cross-over, comparative, pharmacokinetic study

Abstract

Objectives: The therapeutic utility of turmeric (Curcuma longa L., Zingiberaceae) is limited due to low bioavailability of its active principal curcuminoids. This study evaluates the pharmacokinetic characteristics of a natural, water-dispersible turmeric extract containing 60% curcuminoids (TurmXtra 60N), referred to as WDTE60N, compared to standard turmeric extract 95% (STE95).

Methods: This open-label, two-way crossover, single oral dose, comparative pharmacokinetic study, randomized 14 subjects to receive one capsule of WDTE60N (150 mg curcuminoids) or three capsules of STE95 (500 mg curcuminoids each). The resulting dose ratio of actives for WDTE60N:STE95 was 1:10.

Key findings: Peak plasma levels of free curcumin, total curcuminoids, tetrahydrocurcumin and demethoxycurcumin were similar (P > 0.05). Cmax of total curcumin was higher (P = 0.0253) for WDTE60N at a 10-fold lower dose compared to STE95 (43.5 ± 28.5 vs. 21.3 ± 10.7 ng/ml). Mean AUC0-t was higher (P < 0.001) for free curcumin and comparable for total curcumin and total curcuminoids with WDTE60N than with STE95. Five adverse events were reported in three subjects (mild in severity) and were unrelated to study products.

Conclusion: WDTE60N showed higher absorption and comparable exposure for free curcumin, total curcumin and total curcuminoids at a 10-fold lower dose than STE95.

Keywords: Zingiberaceae; bioavailability; curcumin; free curcumin; low dose; turmeric extract.