Comprehensive characterization of Xuebijing injection and comparative analysis of its systemic exposure in patients with severe pneumonia, sepsis, and acute pancreatitis

• UPLC-MS profiles 55 chemical constituents in Xuebijing Injection. • Systemic exposure to XBJ components differs across pneumonia, sepsis, and pancreatitis. • Hydroxysafflor yellow A and paeoniflorin are major systemic components across diseases. This study aimed to investigate the chemical constituents of Xuebijing Injection and compare differences in its systemic exposure components among patients with severe pneumonia, sepsis, and acute pancreatitis during the steady-state blood concentration phase. Using ultra-high-performance liquid chromatography-mass spectrometry, compounds were identified and analyzed based on retention time, accurate molecular weight, secondary mass spectrometry fragmentation patterns, and comparisons with reference standards and databases. A total of 55 chemical constituents were identified in Xuebijing Injection, primarily flavonoids, organooxygen compounds, prenol lipids, and isobenzofurans. In patient plasma, 16 components were detected in severe pneumonia patients, comprising 7 prototypes, 6 Phase I metabolites, and 3 Phase II metabolites; 32 components were found in acute pancreatitis patients, including 12 prototypes, 10 Phase I metabolites, and 10 Phase II metabolites; and 24 components were identified in sepsis patients, consisting of 8 prototypes, 9 Phase I metabolites, and 4 Phase II metabolites. Acute pancreatitis patients exhibited the highest number of systemic exposure components, followed by sepsis and severe pneumonia patients. Hydroxysafflor yellow A, paeoniflorin, and neocnidilide glucuronidation were consistently detected at relatively high concentrations across all groups. This study demonstrates the utility of ultra-high-performance liquid chromatography-mass spectrometry for rapid profiling of the chemical composition of Xuebijing Injection and its blood-exposed components, providing a reference for elucidating its pharmacodynamic material basis and mechanism of action.