Pharmacokinetics and absolute bioavailability of curcumin in rats

Aim To study the pharmacokinetics and absolute bioavailability of curcumin in rats with different administration.Methods A HPLC method was developed for the determination of curcumin in rat plasma.Oral,intraperitoneal and ranine vein doses of 200,20 mg·kg-1 and 10 mg·kg-1 were respectively administered,and the concentrations of curcumin were determined with HPLC.The pharmacokinetic parameters were calculated with the program DAS 2.0.The absolute bioavailability of curcumin was calculated according to AUC(0-∞) and the doses of curcumin following oral,intravenous and intraperitoneal administration.Results Excellent linear relationship was obtained in the range of 0.05~6.00 mg·L-1(r=0.9998).The lower limit determination of curcumin was 0.05 mg·L-1.The relative recoveries were(99.29±5.40)%,(104.21±4.72)% and(99.83±1.97)%respectively at three concentrations(0.10 mg·L-1,1.00 mg·L-1,4.00 mg·L-1).The intra-day RSD were 4.49%,3.90%and 1.72%.The inter-day RSD were 4.61%,4.27% and 2.00% respectively.The metabolic processes of curcumin in rats all fit in with the two-compartment model following oral,intravenous and intraperitoneal administration.Elimination half life were(159.28±18.12),(90.79±11.55),(11.96±2.64) min respectively and AUC(0-∞) were(86.36±12.90) mg·min·L-1,(73.39±8.72) mg·min·L-1,(104.62±11.89) mg·min·L-1 respectively.The absolute bioavailability of intraperitoneal administration was 35.07% and the absolute bioavailability of intragastric administration was 4.13%.Conclusion With different administration,the pharmacokinetics process of curcumin is similar in rats.The absolute bioavailability of intraperitoneal administration is relatively high,while the absolute bioavailability of intragastric administration is low.