Influence of dosage forms on pharmacokinetics of daidzein and its main metabolite daidzein-7-O-glucuronide in rats.
OBJECTIVE
To investigate the influence of dosage forms on the pharmacokinetics of daidzein and its main metabolite daidzein-7-O-glucuronide in Wistar rats.


METHODS
After administration of two typical dosage forms (daidzein solution and suspension), the concentrations of daidzein and daidzein-7-O-glucuronide were determined by an LC-MS-MS method. The pharmacokinetic parameters were calculated and analyzed statistically using the Student's t-test.


RESULTS
Absorption of daidzein after administration of daidzein solution (tmax=0.46 h) was more rapid than that of the suspension (tmax=5.00 h). The peak plasma concentrations of daidzein after administration of daidzein solution and suspension were 601.1 microg/L and 127.3 microg/L, respectively, and those of daidzein-7-O-glucuronide were 3000 microg/L and 192.6 microg/L, respectively. The absolute bioavailabilities of free daidzein in rats after administration of daidzein solution and suspension were 12.8% and 6.1%, respectively, which were calculated to be 47.0% and 12.2%, respectively, in the form of total daidzein (free plus conjugated daidzein).


CONCLUSIONS
Absorption of daidzein solution was better than absorption of suspension (P<0.05).
Qiu
Feng
F
Laboratory of Drug Metabolism and Pharmacokinetics, Shenyang Pharmaceutical University, Shenyang 110016, China.
Chen
Xiao-yan
XY
Song
Bo
B
Zhong
Da-fang
DF
Liu
Chang-xiao
CX
D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000378:metabolism / Q000493:pharmacokinetics*; D001682:Biological Availability; D002853:Chromatography, Liquid; D005260:Female; D007529:Isoflavones / Q000008:administration & dosage / Q000378:metabolism / Q000493:pharmacokinetics*; D008297:Male; D013058:Mass Spectrometry; D051381:Rats; D017208:Rats, Wistar; D013535:Suspensions
D000972:Antineoplastic Agents, Phytogenic; D007529:Isoflavones; D013535:Suspensions; C004742:daidzein