EFFECT OF A CHINESE HERBAL FORMULATION ON THE PHARMACOKINETICS OF PARACETAMOL IN RATS

Abstract

The effect of a Traditional Chinese herbal formulation, K-601, on the pharmacokinetics of paracetamol (acetaminophen) was investigated. A simple high performance liquid chromatography-single quadrupole mass spectrometric (LC/MS) analytical method was developed, validated according to ICH guidelines and applied for the pharmacokinetics determination of paracetamol in the plasma of rats. The results of the pharmacokinetics revealed significant differences in all the parameters compared. It was observed that co-administering paracetamol with K-601, the half-life (t1/2), the time of maximum concentration (Tmax), the area under concentration-time curve (AUC), the mean residence time (MRT) and the volume of distribution (Vd) were lower than those from the paracetamol-alone treated group. The maximum plasma drug concentration (Cmax) and clearance (CL) however were higher than those from the paracetamol-alone treated group. In conclusion, K-601 was found to significantly affect the metabolism of paracetamol in the liver.