RESUMO
Objective To establish a sensitive method for the determination of rhodamine 123 (Rh123) in rat plasma by high performance liquid chromatography (HPLC).Methods The plasma samples were extracted by acetonitrile,and then separated on a Hypersil BDS C18 colunm (4.6 mm×100 mm,5 μm) equipped with a guard column kept at 25 ℃.The mobile phase consisted of acetonitrile and phosphate buffer (0.02 mol·L-1,pH4.0) (60:40) and was pumped at a constant rate of 1.0 mL·min-1.The peak was detected using a fluorescence detector set at FLD1A:Ex=485 nm,Em=546 nm.Results In this study,the method was validated for the Rh123 range of 0.1 to 32.0 μg·L-1,and the lower limit of quantitation (LLO Q) was 0.1 μg·L-1.The intra-and inter-day precisions for Rh123 were less than 7%,and the mean recoveries of Rh123 were 87.93%,89.03%,86.11% at low,mid,and high concentrations,respectively.Conclusion A simple,rapid and reproducible HPLC method was developed for the determination of Rh123 in rat plasma,which was an applicable method in modeling and description of the possible pharmacological interactions between the medicines and P-glycolprotein transporter.