Objective To investigate the relationship between the physical properties of Jinzhen Oral Liquid (金振口服液) intermediates and their total solid content (TSC) and the contents of effective components, and to establish a content prediction model, thereby providing a reference for rapid quality evaluation of intermediates. Methods Samples were collected from two types of extracts (mineral-botanical and artificial cow bezoar) and four key manufacturing steps (hot mixing, refrigeration, centrifugation, and filling). Six physical parameters (density, viscosity, surface tension, electrical conductivity, refractive index, and pH value) were measured, alongside the contents of six effective components (baicalin, wogonoside, glycyrrhizic acid, gallic acid, hyodeoxycholic acid, and cholic acid) and TSC. Correlation analysis was performed, and polynomial regression models were developed for the overall process, the mineral-botanical extract, and the artificial cow bezoar extract, respectively. Results Correlation analysis indicated that most physical parameters were significantly correlated with chemical components throughout the entire preparation process. Refractive index showed a strong correlation with TSC (r = 0.845), while density was correlated with TSC and baicalin with coefficients of 0.529 and 0.505, respectively. In mineral-botanical extracts, the correlation coefficient between refractive index and TSC was 0.525. In artificial cow bezoar extracts, refractive index was correlated with TSC, hyodeoxycholic acid, and cholic acid, with coefficients of 0.759, 0.729, and 0.593, respectively. The regression models established based on refractive index performed well in validation: the model for TSC in the full process showed a mean relative error (MRE) of 4.04% and a mean absolute error (MAE) of 1.10%. The MRE values for the baicalin and wogonoside models were both below 10%, and both passed the F-test. The MRE values for the TSC models in both mineral-botanical and artificial cow bezoar extracts were below 6%. Conclusion The refractive index of Jinzhen Oral Liquid intermediates shows significant correlation with both TSC and the contents of effective components. The refractive index method is a feasible approach for predicting TSC and the contents of baicalin and wogonoside during the manufacturing process, as well as TSC in both extracts. This study provides a novel strategy for the rapid quality assessment of Jinzhen Oral Liquid production and offers a technical basis for the practical application of online refractometry.

Jinzhen Oral Liquid  /  physical properties  /  effective components  /  total solid content  /  rapid quality evaluation  /  refractive index  /  baicalin  /  wogonoside  /  glycyrrhizic acid  /  gallic acid  /  hyodeoxycholic acid  /  cholic acid