Unveiling the comprehensive alterations in the in vivo components, tissue distribution profiles, and pharmacokinetic characteristics between Jiawei Erzhi formula and Erzhi formula.

Jiawei formula holds a prevalent position in clinical application of Chinese medicine. However, there is a notable lack of methodologies capable of effectively revealing the metabolic discrepancies between the base formula and its Jiawei-modified counterpart. Erzhi formula (EZF) is a tonic formulation, and incorporation of Spatholobi Caulis and Achyranthis Bidentatae Radix yields Jiawei Erzhi formula (JWEZF), which exhibits augmented pharmacological efficacy. This study was devised to formulate a strategy facilitating a thorough comparison of the in vivo components, tissue distribution patterns, and pharmacokinetic behaviors of JWEZF and EZF in rats. Specifically, comprehensive in vivo components analysis was executed utilizing ion mobility liquid chromatography/mass spectrometry, complemented by automated peaks annotation workflows. The distribution of primary components in rat's heart, liver, kidney, and spleen was visualized through desorption electrospray ionization-mass spectrometry imaging (DESI-MSI). Additionally, pharmacokinetic variations in rat plasma were elucidated employing scheduled multiple reaction monitoring (sMRM). Overall, we successfully identified 129 prototype compounds (128 in JWEZF and 89 in EZF) along with 140 metabolites (41 unique for JWEZF). Moreover, DESI-MSI detected differences in the in situ tissue distribution of seven components between EZF and JWEZF, with JWEZF showing a likely higher tissue exposure. Pharmacokinetic analysis of 21 prototypes and six associated metabolites indicated analogous pharmacokinetic profiles between EZF and JWEZF; however, the plasma exposure of isochlorogenic acid B, neochlorogenic acid, luteolin-7-O-glucoside, and its metabolite was significantly higher in the JWEZF group. In summary, we have established a methodology to delve into the distinctions between the original formula and its Jiawei-modified variant.