Improved quality control method for prescriptions of Polygonum capitatum through simultaneous determination of nine major constituents by HPLC coupled with triple quadruple mass spectrometry.

ABSTRACT

As a traditional Miao-nationality medicinal plant, Polygonum capitatum has been used in clinical practice for several thousand years. Its prescriptions, including three dosage forms granules, capsule and tablet are known by the brand name Relinqing® and have played an indispensable role in the treatment of urinary system infection, pyelonephritis and kidney stones. However, no study about the comprehensive quality evaluation of Relinqing® has been reported. In the present paper, a method for the simultaneous determination of nine major compounds in three dosage forms of Relinqing® using HPLC coupled with triple quadrupole mass spectrometry (HPLC-QQQ MS) was established to comprehensively evaluate their quality. The nine compounds, including four phenolic acids, four flavonoids and a lignin, were analyzed with acceptable linear regression relationship (r², 0.9923-0.9992), precision (RSD, 1.25%-2.78%), repeatability (RSD, 2.05%%-3.47%), stability (RSD, 1.84%-3.72%) and recovery (93.60%-108.54%, RSD ≤ 3.67%). The present study fills the gap in the multivariate quality control of Relinqing® and provides a valuable reference for quality standards and dosage reforming of this traditional Chinese medicine.