Abstract: AIM: To study the pharmacokinetic profiles of ropivacaine methanesulfonate in patients and research the sex differences between these parameters. METHODS: 15 mL ropivacaine methanesulfonate injection was given when the patient had an epidural anesthesia.The concentrations of ropivacaine in plasma were determined by HPLC.The parameters of pharmacokinetics were calculated by DAS software. RESULTS: The pharmacokinetic parameters of male and female after administration with ropivacaine methanesulfonate injection were as follows:the t_1/2β were (4.050±2.548) and (2.088±0.135)h;the t_1/2Ka were (0.085±0.045) and (0.107±0.069)h;the t_max were (0.333±0.118) and (0.417±0.167)h; the C_max were (1.066±0.135) and (1.113±0.317) mg/L;the AUC_0-tn were (2.856±0.321) and (2.369±0.386)mg·L^-1·h;the MRT0-tn were (2.070±0.113) and (2.022±0.089)h, respectively. CONCLUSION: The methodology to determine plasma concentration by HPLC and pharmacokinetic profiles of ropivacaine methanesulfonate injection were achieved. The results showed that there were no sex differences statistically between the pharmacokinetic parameters.

Key words: ropivacaine methanesulfonate, pharmacokinetics, sex difference, plasma concentration, high performance liquid chromatography