Objective To systematically investigate the intestinal absorption characteristics of baicalin, glycyrrhizic acid, aloe-emodin, wogonin, emodin and chrysophanol in Jinzhen Oral Liquid (金振口服液) using the rat in situ single-pass intestinal perfusion model and Caco-2 cell model. Methods In vitro experiments were conducted using Caco-2 monolayer cell model to preliminarily evaluate the absorption capacity of the six components through apparent permeability coefficient (P_app). In situ experiments were conducted using rats in situ intestinal perfusion to further verify the absorption of the six components in rat intestinal segments (duodenum, jejunum, ileum, and colon) through the absorption rate constant (K_a) and effective permeability coefficient (P_eff). The in vitro and in situ absorption rules were compared and analyzed to clarify their absorption mechanisms. Results The in vitro and in situ experimental results showed good consistency. Under low-, medium-, and high-concentration perfusion conditions, all six components were absorbable in various intestinal segments of rats. Among them, the P_eff values in the duodenum, jejunum, and colon were all greater than 1.2 × 10⁻³ cm/min, indicating that the six components were well absorbed in these three intestinal segments. In the ileum segment, the P_eff values of baicalin, glycyrrhizic acid and wogonin were 1.8 × 10⁻⁴—1.2 × 10⁻³ cm/min, indicating moderate absorption of these three components in the ileum. The P_eff values of aloe-emodin, emodin and chrysophanol were greater than 1.2 × 10⁻³ cm/min, indicating good absorption of these three components in the ileum. In addition, there were differences in the absorption mechanisms of these six components, and most of them exhibited absorption characteristics that required carrier involvement, such as active transport and diffusion promotion (some of which were concentration dependent or saturated). At the same time, there were also components that mainly participate in passive diffusion or both active and passive transport. Conclusion In situ and in vitro intestinal absorption experiments reveal the segment-specific absorption patterns of six major components in Jinzhen Oral Liquid, with good overall absorption that meets the requirements for oral preparations.

Jinzhen Oral Liquid  /  intestinal absorption characteristics  /  in situ single-pass intestinal perfusion  /  Caco-2 cell model  /  baicalin  /  glycyrrhizic acid  /  aloe-emodin  /  wogonin  /  emodin  /  chrysophanol