Simultaneous quantification of l‐tetrahydropalmatine and its urine metabolites by ultra high performance liquid chromatography with tandem mass spectrometry

Abstract

l-tetrahydropalmatine (l-THP) is a tetrahydroprotoberberine isoquinoline alkaloid that has been used as an analgesic agent in China for more than 40 years. Recent studies indicated its potential application in the treatment of drug addiction. In this study, a sensitive and rapid method using ultra high performance liquid chromatography with MS/MS was developed and validated for simultaneous quantitation of l-THP and its desmethyl metabolites. Enzymatic hydrolysis was integrated into sample preparation to enable the quantitative determination of both free and conjugated metabolites. Chromatographic separation was achieved on an Agilent Poroshell 120 EC-C18 column. Detection was performed by MS in the positive ion ESI mode. The calibration curves of the analytes were linear (r(2) > 0.9936) over the concentration range of 1-1000 ng/mL with the lower limit of quantification at 1 ng/mL. The precision for both intra- and interday determinations was <8.97%, and the accuracy ranged from -8.74 to 8.65%. The recovery for all the analytes was >70% without significant matrix effect. The method has been successfully applied to the urinary excretion study of l-THP in rats. The conjugates were found to be the major urine metabolites of the drug.

Development and validation of a high performance liquid chromatography quantification method of levo‐tetrahydropalmatine and its metabolites in plasma and brain tissues: application to a pharmacokinetic study

“…In addition, our pharmacokinetic data indicated that L-THP and its metabolites exhibit high permeability across the blood-brain barrier, evidenced by AUC brain/ plasma values that ranged between 6.6-and 16.7-fold ( Table 6). The most significant and prominent metabolites in plasma are only L-CP and L-CD (Xiao et al, 2014), which is consistent with our results and suggests that the contribution from the metabolic Xiao et al, 2014). It is to be mentioned that L-THP has four monodesmethyl metabolites: L-ICP, L-CP, L-THB and L-CD.…”

“…Further investigations on the plasma exposure and clearance pathway of these active metabolites are crucial for better understanding of the pharmacological mechanism of L-THP (Xiao et al, 2014). Further investigations on the plasma exposure and clearance pathway of these active metabolites are crucial for better understanding of the pharmacological mechanism of L-THP (Xiao et al, 2014).…”

“…The pharmacokinetic and pharmacodynamics of L-tetrahydropalmatine have been extensively studied for decades; however, only a few metabolic studies have been reported (Hong et al, 2010;Li, Ye, Bi, & Guo, 2006;Xiao et al, 2014;). Full understanding of L-THP metabolism is critical to evaluate its safety and efficacy.…”

“…For example, methods for the quantification of L-THP and/or its metabolites in rat bile (Yun-Ya & Yang, 2009), Penicillium janthinellum (Li et al, 2006), urine (Xiao et al, 2014), (Hong et al, 2010), rat plasma (Fan, Xie, & Zhang, 2006;Liao, Chang, Yin, Wang, & Meng, 2014;Xiao et al, 2014;), rat striatum (Wang et al, 2012a, b) and human plasma (Chao- Yu et al, 2014) have been reported. For example, methods for the quantification of L-THP and/or its metabolites in rat bile (Yun-Ya & Yang, 2009), Penicillium janthinellum (Li et al, 2006), urine (Xiao et al, 2014), (Hong et al, 2010), rat plasma (Fan, Xie, & Zhang, 2006;Liao, Chang, Yin, Wang, & Meng, 2014;Xiao et al, 2014;), rat striatum (Wang et al, 2012a, b) and human plasma (Chao- Yu et al, 2014) have been reported.…”

Simultaneous determination of l‐tetrahydropalmatine and its active metabolites in rat plasma by a sensitive ultra‐high‐performance liquid chromatography with tandem mass spectrometry method and its application in a pharmacokinetic study

“…Although earlier research have described method for determination of several metabolites of L-THP by LC-MS/MS (Xiao et al ., 2014), they mainly focued on the urinary excretion. The quantitative determination and pharmacokinetic profile for active metabolites in plasma had not been thoroughly studied.…”