Study On The Pharmacokinetics Of New Compound Folium Isatidis Tablets By HPLC-MS/MS

Objective:New Compound Folium Isatidis Tablet, which is composed of traditional Chinese medicine and chemical compounds including acetaminophen, caffeine, amobarbital and vitamin C, is widely used in clinic in China. Our study mainly focuses on the pharmacokinetics of acetaminophen, caffeine and amobarbital in the New Compound Folium Isatidis Tablets. When these three compounds were used alone separately, their own pharmacokinetics characteristics were also studied, and the differences from that in the New Compound Folium Isatidis Tablets were compared. The prescription rationality of the New Compound Folium Isatidis Tablets was also analyzed.Methods:According to the "Guidelines on quantitative analytical method validation of biological samples" in Chinese pharmacopoeia （2015）, one method was established for the determination of paracetamol, caffeine and amobarbital in rat plasma using HPLC-MS/MS, and the specificity, precision, accuracy, linearity, stability, quantitative limit and biological matrix effect were all verified. By using the method, the pharmacokinetics of the main component in New Compound Folium Isatidis Tablets were studied. The experimental rats were divided into four groups:New Compound Folium Isatidis Tablets oral administration group, acetaminophen oral administration group, caffeine oral administration group and amobarbital oral administration group. Plasma samples from the orbital venous plexus in 12 hours after administration were analyzed using the established HPLC-MS/MS method. All data were analyzed using WinNonlin 6.2 software and statistical data were analyzed using SPSS Statistics Version 22 to compare T_max, C_max and AUC among all groups.Results:Linear ranges of this HPLC-MS/MS method were 0.1 μg/ml-100 μg/ml for acetaxninophen,0.01μg/ml-10 μg/ml for caffeine and 0.01μg/ml-10 μg/ml for amobarbital, respectively, and all the linear regression coefficient were above 0.99. The lower limit of quantification was 0.1 μg/ml for acetaxninophen,0.01 μg/ml for caffeine and 0.01 μg/ml for amobarbital, respectively. The intra-assay and inter-assay precision （CV） and accuracy （RE） were all within 15%. The result indicated that this method meet the requirements of "Guidelines on quantitative analytical method validation of biological samples" in Chinese pharmacopoeia （2015）. After oral administration of New Compound Folium Isatidis Tablets （0.7 pill/kg）, the pharmacokinetics of three compounds in rats were calculated, and the results were as follows:T_max of acetaminophen was 0.333±0.129 （n=6）, C_max of acetaminophen was 33.117±10.421 （n=6）, AUC of acetaminophen was 32.167±6.137 （n=6）; T_max of caffeine was 0.583±0.342 （n=6）, C_max of caffeine was 5.632±0.531 （n=6）, AUC of caffeine was 15.800±2.989 （n=6）; T_max of amobarbital was 0.333±0.129 （n=6）, C_max of amobarbital was 1.868±0.622 （n=6）, AUC of amobarbital was 1.697±0.237 （n=6）. Compared to the pharmacokinetic parameters of caffeine when it was administrated alone, the pharmacokinetic parameters of caffeine when it was administrated as component part of New Compound Folium Isatidis Tablets showed no significant difference. Compared to the pharmacokinetic parameters of amobarbital when it was administrated alone, the pharmacokinetic parameters of amobarbital when it was administrated as component part of New Compound Folium Isatidis Tablets also showed no significant difference. T_max of acetaminophen when it was used as component part of New Compound Folium Isatidis Tablets did not display significant difference with T_max of acetaminophen when it was used alone. But, C_max and A UC of acetaminophen as component part of New Compound Folium Isatidis Tablets were all lower than C_max and AUC of acetaminophen when it was used alone.Conclusion:One HPLC-MS/MS method was firstly established to determine acetaminophen, caffeine and amobarbital in rat plasma, and the method was successfully applied to the New Compound Folium Isatidis Tablets pharmacokinetics study in rats. According to this study, the bioavailability of caffeine or amobarbital was at the same content whether they were used alone separately or they were used as component part of New Compound Folium Isatidis Tablets. Compared to the bioactivity of acetaminophen when it was used alone, the bioactivity of acetaminophen was little lower when it was used as component part of New Compound Folium Isatidis Tablets. So, the dosage of acetaminophen in New Compound Folium Isatidis Tablets was higher than the regular dosage when it was used alone to treat cold. The dosage of caffeine in New Compound Folium Isatidis Tablets was also higher than the regular dosage when it was used alone because of the antagonistic effects of amobarbital. In all, the prescription of the New Compound Folium Isatidis Tablets is reasonable.