Pharmacokinetics Of Purified Paeonol And Paeonol In Moutan Cortex Decoction And Rhuborbmoutan Decoction

Objective:1.To prepare Moutan Cortex decoction and Rhuborbrnoutan decoction,and to establish HPLC-UV methods for the determination of paeonol in Moutan Cortex decoction,Rhuborbrnoutan decoction,human and mice plasma.2.To study the pharmacokinetics of paeonol in Chinese healthy volunteers after a single dose of 160mg paeonol tablets.3.To study the pharmacokinetics of paeonol in Chinese healthy volunteers after a single dose of 160mg paeonol tablets at dining and fasting conditions and to evaluate the influence of food on paeonol pharmacokinetic characteristics.4.To evalute the pharmacokinetic characteristics of purified paeonol,paeonol in Moutan Cortex decoction and Rhubarbmoutan decoction in mice.Methods:1.Mutan Cortex decoction and Rhubarbmoudan decoction were prepared and the contents of paeonol were determined by HPLC-UV methods.2.24 Chinese healthy volunteers were screened and 4mL blood was collected before and 0.25,0.5,0.75,1,1.25,1.5,1.75,2,2.25,2.5,2.75,3h after a single oral dose of 160mg paeonol tablets.The paeonol in plasma was determined by HPLC-UV methods and its main pharmacokinetic parameters were calculated and evaluated by DAS 2.0. 3.6 Chinese healthy volunteers were devided into two growps according to two period cross-over design test and orally given 160mg paeonol at dining and fasting conditions.4mL blood was collected at scheduled time after a single oral dose of 160mg paeonol tablets The paeonol in plasma was determined by HPLC-UV method and the main pharmacokinetic parameters of paeonol were calculated by DAS 2.0 and the influences of food on pharmacokinetics of paeonol were evaluated.4.180 male mice of 22～28g weight were devided into three growps and purified paeonol,Moutan Cortex decoction and Rhuborbmutan decoction were administered intragastricly equivalent to 10mg/kg of paeonol.A liquor of blood was collected and the concentrations of paeonol in plasma was determined with HPLC-UV method.The main pharmacokinetic parameters of paeonol were calculated by DAS 2.0 and the influences of other components in Mutan Cortex and in Rhuborbmutan decoction were evaluated.Results:1.The contents of paeonol in Mutan Cortex was 1.5mg/mL.and in Rhuborbmutan decoction was 0.3mg/mL.2.The linear range of the calibration curve for paeonol in human plasma was 10～500ng/mL,and the low limit of quantitation(LLOQ)was 10ng/mL.The regression equation was Y=-11652.36607+5207.71572X(r=0.9998).The absolute and relative recoveries were 84.86%～86.13%and 92.28～97.44%,respectively. Intra-day and inter-day RSDs were less than 13.72%.Paeonol in plasma was stable at -20℃for 24 hours and 7 days,with the RSD of less than 10.46%and stabled after two freeze-thawing cycles,with the RSD of less than 8.4%.The main pharmacokinetic parameters of paeonol after single oral dose of 160mg paeonol tablets were as follows:t_1/21.09±0.62h,Tmax 1.03±0.15h,Cmax 111.16±41.24ng/mL, AUC_0-t171.26±42.63ng·h/mL,AUC_0-∞220.27±67.24ng·h/mL,respectively.3.The main pharmacokinetic parameters of paeonol after single oral dose of 160mg paeonol tablets at dining and fasting condition were as follows:t_1/21.01±0.67h and 1.97±1.12h,Tmax 1.87±0.38h and 1.04±0.10h,Cmax 57.77±3.75 ng/mL and 77.69±25.80 ng/mL,AUC_0-t89.95±7.78 ng·h/mL and 132.05±46.44 ng·h/mL,AUC_0-∞ 125.97±23.39 ng·h/mL and 199.95±71.70 ng·h/mL,respectively.4.The main pharmacokinetic parameters of paeonol in mice after purified paeonol, Moutan Cortex decoction and Rhuborbmutan decoction at 10mg/kg of paeonol were as follows:t_1/2,13.15±2.48min,15.04±4.40min and 21.83±6.21min,Tmax,15min,15 min and 10min,Cmax,69.41±4.50 ng/mL,82.90±6.10ng/mL and 123.32±5.55ng/mL, AUC_0-t,1243.42±109.751 ng·min/mL,1412.74±97.723ng·min/mL and 2162.198±105.1 ng·min/mL,AUC_0-∞,2192.456±472.182 ng·min/mL,2659.571±1590.703ng·min/mL and 3423.361±465.409ng·min/mL,respectively.Conclusion:1.The contents of paeonol was 1.5mg/mL in Mutan Cortex decoction and 0.3 mg/mL in Mutan Cortex decoction.2.The established HPLC-UV methods were sensitive,convenient and suitable for the determination of paeonol in human plasma.The pharmacokinetic parameters can provied theory evidence for clinical application.3.The pharmacokinetic parameters of paeonol in human body were variable at dining and fasting conditions,that Tmax was prolonged from 1.04±0.10h to 1.87±0.38h while t_1/2,AUC,Cmax were decreased by food,indicating that dosage regiment should be adjusted or modified at dining condition.4.The main pharmacokinetic parameters of purified paeonol paeonol in Moutan Cortex decoction and Rhuborbmutan decoction at 10mg/kg paeonol were 13.15±2.48min,15.04±4.40min and 21.83±6.21min for t_1/2,15min,15min and 10min for Tmax,69.41±4.50 ng/mL,82.90±6.10ng/mL and 123.32±5.55ng/mL for Cmax, 1243.42±109.751 ng·min/mL,1412.74±97.723ng·min/mL and 2162.198±105.1 ng·min/mL for AUC_0-t,2192.456±472.182 ng·min/mL,2659.571±1590.703 ng·min/mL and 3423.361±465.409ng·min/mL for AUC_0-∞,respectively,indicating that disposition in mice were affected by other compenents in crude drug and in recipe.