Objective To establish analytical method for the determination of tramadol and its metabolite O - demethyltramadol in human plasma and urine by RP - HPLC. Methods Separation was carried out ons a zorbax RP - select B column and the mobile phase was a mixture of 0. 05 mol · L~(-1) potassium dihydrogen phosphate ( adjusted to pH 4. 0 with phosphoric acid)-acetonitrile (90: 10). The flow rate was 1 mL · min~(-1). Fluormetric detection was performed at excitation and emission wavelengths of 216 run and 308 nm, respectively. Results In plasma, the calibration curve was linear within 12. 5 - 800. 0 ng · mL~(-1) for tramadol and 5 -320 ng · mL~(-1) for O - demethyltramadol. The absolute recoveries were all higher than 86% , and the relative recoveries were from 93% to 105%. The RSD of the within - day and between - day variations were lower than 9% and 8% , respectively. In urine, the calibration curve was linear within 12. 5 -4 000 ng · mL~(-1) for tramadol and 5 -1 280 ng · mL~(-1) for O -demethyltramadol. The absolute recoveries were all higher than 80% , and the relative recoveries were from 91% to 107%. The RSD of the within-day and between-day variations were lower than 9%. For stability test in plasma and urine, the difference of the results was within 10%. Conclusion This RP - HPLC method is simple, sensitive, accurate and specific.

Hepatic fibrosis is a common complication of chronic liver disease， seriously affecting patients' quality of life and leading to severe consequences such as cirrhosis and liver cancer. Modern medicine has made progress in the treatment of hepatic fibrosis， while it still faces certain challenges and limitations. Therefore， seeking new therapeutic strategies is of great clinical significance. The nuclear factor-κB （NF-κB） signaling pathway plays a role in regulating inflammation and immune responses. Recent studies have shown that the NF-κB signaling pathway plays a key role in the occurrence and development of hepatic fibrosis. The abnormal activation of the NF-κB signaling pathway leads to the overexpression of genes related to liver inflammation and fibrosis， thereby promoting the development of hepatic fibrosis. Traditional Chinese medicine （TCM） is a traditional treatment method with unique advantages and potential. In recent years， increasing studies have proved that TCM can treat hepatic fibrosis by regulating the NF-κB signaling pathway. The active ingredients in Chinese herbal medicines can intervene in the activation of the NF-κB signaling pathway to inhibit inflammatory responses， thereby reducing the severity of hepatic fibrosis. This article reviews the mechanisms of TCM in treating hepatic fibrosis via the NF-κB signaling pathway and evaluates the efficacy and discusses the clinical application prospects of relevant Chinese herbs and formulae， aiming to provide references for further research and clinical practice.