Comparative pharmacokinetics of eight major bioactive components in normal and bacterial diarrhea mini-pigs after oral administration of Gegen Qinlian Decoction.

Healthy animals are most widely used in current pharmacokinetic(PK) studies. However, neglecting the effects of specific diseases on drug absorption results in the PK parameters of those experiments not accurately reflecting in vivo drug concentration changes during treatment. In this study, an E. coli infective diarrheal minipig model was applied to explore the pharmacokinetics of Gegen Qinlian decoction (GQD). A simple and rapid ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed to determine the concentrations of the eight GQD components in minipig plasma after intragastric administration of GQD. The PK parameters of the main GQD components in normal and model minipigs after oral administration of GQD were compared. There were statistically significant differences (p<0.05) in the pharmacokinetic parameters of Puerarin, Wogonin and Daidzein involving the AUC0-t, Cmax, MRT(0-t), t1/2z between normal and model minipigs. Results showed that bacterial diarrhea had a great impact on the biological availability of the main ingredients in GQD. More importantly, the results obtained suggest that the bacterial diarrheal minipig model can be successfully applied in PK studies and may be used in other PK studies of drugs targeting intestinal disease.