Abstract
ABSTRACT
Objective
This study aims to systematically evaluate the in vitro stability and pharmacokinetic behavior of representative polyphenols in Qingzhuan dark tea (QDT) and to explore the relationship between physicochemical stability and systemic exposure.
Methods
Twelve representative polyphenols, including eight catechins and four theaflavins, were evaluated using a three‐factor, three‐level L
9
orthogonal design to investigate the effects of pH, temperature, and time on stability. Based on stability and plasma detectability, seven catechins were further investigated in male Sprague–Dawley rats following oral administration of QDT extract at doses of 1, 2, and 3 g/kg. A validated liquid chromatography–mass spectrometry (LC‐MS) method was used for quantitative analysis and pharmacokinetic evaluation.
Results
The optimal preservation condition for the QDT extract and mixed standards was pH 5, 4°C, and 30 min. The analytical method showed satisfactory linearity (
r
> 0.9908), precision (max
and AUC generally increased with increasing dose, indicating dose‐dependent systemic exposure.
Conclusion
The integrated stability and pharmacokinetic evaluation establishes a link between physicochemical stability and biological disposition of QDT polyphenols, providing a scientific basis for QDT storage optimization, quality control, formulation development, and functional application.