Study on pharmacokinetics of puerarin in rats by following different methods of administration of puerariae extract

Objective: To study pharmacokinetics of Puerarin in Rats Following Different Methods of Administration of Puerarin Extract.Methods: Rats received 20 mg/kg puerarin extract by caudal vein injection,20 mg/kg puerarin extract by nasal administration and 200 mg/kg puerarin extract by oral administration.Plasma samples were extracted with methanol and the plasma concentration of puerarin was analyzed by RP-HPLC.The pharmacokinetic parameters and bioavailability were calculated with Kinetica software.Results: Within range of(0.05315-53.1500) mg/L,puerarin presented a fine linear relationship(r=0.9999).The average recovery of puerarin was 95.72% with RSD 2.3%.The main pharmacokinetic parameters were as follows: caudal vein injection: AUC=(795.41±59.85)mg·L-1·min-1,Cmax=(65.74±7.71)μg/mL,MRT=(18.96±2.08)min,t1/2=(16.95±3.55)min,nasal administration: AUC=(227.34±19.42)mg·L-1·min-1,Cmax=(3.78±1.80)μg/mL,Tmax=(7.50±2.74)min,MRT=(117.09±38.37)min,t1/2=(22.50±10.60)min;oraladministration: AUC=(732.48±471.57)mg·L-1·min-1,Cmax=(3.53±1.32)μg/mL,Tmax=(27.00±16.43)min,MRT=(394.22±209.24)min,t1/2=(237.84±112.39)min.Conclusion: There were significant differences among the main pharmacokinetic parameters of puerarin following different methods of administration of puerarin extract,nasal administration could lead to a quick absorption and its bioavailability was higher than oral administration,this result can provide some scientific basises for the method of administration and the reform of dosage form of puerarin extract.