Pharmacokinetics of curcumin in Thai healthy volunteers following Multiple Administration of curcuminoids tablets

Abstract

Curcumin is daily consumed without any pharmacokinetic evidence in Thais. This study was set up for determining the pharmacokinetic of curcumin in Thai following multiple dosing. Twelve Thai healthy male volunteers were administered curcuminoids tablets 6 grams/day for 8 days. Blood samples were collected on the first, seventh and eighth days, immediately centrifuged and plasma separated was kept frozen for subsequent curcumin analysis, utilized the validated HPLC method. Ethyl acetate was used as an extracting solvent. The extracted curcumin was detected through the C-18 column passing with acetonitrile and methanol in acetic acid as mobile phase. Curcumin was quantitated at 420 nm and having mefenamic acid as an internal standard (IS) detected at 282 nm. The concentrations of curcumin were linear related to response in the range of 0.01-1.0 μg/ml. The intra-day and inter-day accuracy and precision in term of %bias and %RSD were less than 5% and 11% , respectively. No endogenous interference was detected, indicating the specificity of the method. Following curcuminoids administration up to eight day, no any adverse reaction was observed in any subject. The pattern of concentration-time profiles of each subject in three different days were quite similar, implying no accumulation. There were no significant difference of the Tmax, Cmax, AUC, t1/2, Vss and CL values between the first, seventh and eighth day with p-value > 0.05. The mean steady state concentration of curcumin was determined to be 13 nM. At 95% confidence interval, the pharmacokinetic parameters of curcumin in Thais were determined such that the Cmax and Tmax values were 48.37 – 62.40 nM and 2.46 – 5.51 h, respectively; the AUC, Vss and Cl values were 287.0 – 318.1 nM.hr, 347 – 392 L and 51.80 – 58.00 L/h, respectively. Due to the observation of metabolite peak, the pharmacokinetics of metabolites would then be suggested for further study.