Coexisting flavonoids and administration route effect on pharmacokinetics of Puerarin in MCAO rats

A pharmacokinetic comparison was made to evaluate the influence from other components in the Radix Puerariae Extract on pharmacokinetic behavior of Puerarin. Samples of blood and brain were collected by microdialysis and determined by high-performance liquid chromatography-mass spectrometry (MS)/MS. Pharmacokinetic parameters were estimated from the concentration versus time data using non-compartmental methods. In addition, a comparative pharmacokinetic study of Puerarin in stroke rats was studied after administration of the Radix Puerariae Extract via different routes to find an effective way to deliver drug into brain. Obvious pharmacokinetic differences were also observed in comparison between the Puerarin group and the Radix Puerariae Extract group based on middle cerebral artery occlusion (MCAO) rats. The Cmax and area under the curve (AUC) of Puerarin in olfactory bulb of the Extract group significantly reduced when it was intravenously administered. However, the AUCs of Puerarin in plasma are 134.72 and 1707.02 mg/L min, via intranasal and intravenous administration of the Radix Puerariae Extract, respectively. The AUC of the intranasal group in brain is seven times higher than that of intravenous administration. Other ingredients in the Extract may affect the disposition of Puerarin and its transportation through the blood-brain barrier via intravenous administration. But intranasal administration is an effective route to deliver isoflavone-C-glycoside with poor hydrophilicity into brain.