Pharmacokinetic Study of Five Lead Components of Psoraleae Fructus in Human Serum by UHPLC–Q‐TOF‐MS and UHPLC–QqQ‐MS/MS after Oral Administration of Qing'e Pills

A rapid and reliable ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) strategy was established to characterize the chemical constituents of Qing'e Pills in vitro and in vivo. In vitro profiling identified 32 compounds in the Psoraleae Fructus (PF) extract, and 30 compounds related to PF were characterized in the Qing'e Pills extract, mainly belonging to coumarins, dihydroflavones, isoflavones, and chalcones. Following a single oral administration of Qing'e Pills to healthy volunteers, nine prototype compounds were detectable in human serum, confirming systemic exposure to multiple constituents. For quantitative evaluation, a sensitive and selective UHPLC-triple quadrupole-tandem MS (UHPLC-QqQ-MS/MS) method was developed and fully validated for simultaneous determination of five representative analytes (psoralen, isopsoralen [IP], bavachin, neobavaisoflavone, and corylin) in human serum, with osalmid as the internal standard. The validated method was applied to a pharmacokinetic (PK) study in 12 female volunteers receiving Qing'e Pills at the Chinese Pharmacopeia-recommended dose (9 g). Among the monitored analytes, only IP met the quantitative criteria and yielded a complete concentration-time profile, indicating low circulating levels of the remaining components at this clinically relevant dose. Isopsoralen was rapidly absorbed (detectable within 0.5 h), reached a maximum concentration of 85.47 ± 28.96 ng/mL at 1.5 h, and exhibited an area under the curve of 619.52 ± 160.25 ng·h/mL with a terminal half-life of 5.06 ± 0.28 h, suggesting limited systemic exposure with moderate elimination. Collectively, this validated UHPLC-QqQ-MS/MS platform provides a practical approach for chemical profiling and human PK evaluation of coumarins and flavonoids from Qing'e Pills.