2.7. Pharmacokinetic Analysis

The following PK parameters of PTX after oral single dosing to rats were estimated by non-compartmental analysis using WinNonlin^® Professional version 5.2 software (Pharsight Corporation, Mountain View, CA, USA): The area under the plasma concentration-time curve from 0 h to infinity (AUC_inf), elimination half-life (t_1/2), apparent volume of distribution after oral single dosing (Vz/F), oral clearance (Cl/F), maximum plasma concentration (C_max) and the time required to reach C_max (T_max). The relative bioavailability (RB, %) of PTX was calculated with the following formula:

AUC_inf po control is the AUC_inf obtained from oral single administration of PTX alone, and AUC_inf po co-administration is the AUC_inf obtained from oral single co-administration of PTX and compound 5c.