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RT-A and its metabolites RT-B of resveratrol its glycosides (including polydatin), oxo acids derivatives, based on the active ingredient in the natural product resveratrol and their glucosides (polydatin) structural modification to the parent compound, a compound having a high activity, designed to improve cardiovascular function, is under research and development in a new drug candidates. In accordance with the relevant requirements of the New Drug for preclinical pharmacokinetic dynamics studies, we investigated the in vitro stability of the RT-A, for the determination of plasma sample method of quantitative analysis of RT-B, and successful application of this method determined by RT -B in rat plasma protein binding rate. With these basic test, provide the basis for the clinical application of the drug. In this paper, high performance liquid chromatography (HPLC) system to examine the influence of temperature and pH on the stability of the RT-A and its stability in rat plasma. Establish a HPLC method for the determination of buffer solution RT-A, the Kromasil C 18 column, methanol and 0.1% acetic acid (70:30, v / v) as the mobile phase at a flow rate of 1.0 mL / min, the detection wavelength was 318 nm, column temperature of 40 ℃. Its linear range 1-80μg/ml (r = 0.998 3), intra-day and inter-day precision (RSD) were less than 11%, and accuracy (RE) in 6.1%. Chromatographic conditions of HPLC method for determination of plasma RT-A above, its linear range 1-40μg/mL (r = 0.997), intra-day and inter-day precision (RSD) were less than 9.8% accuracy (RE ) at 12.5%. The results show that the stability of the RT-A having a pH and temperature dependent. In a buffer solution of pH 1.5 ~ pH 7.2, RT-A can be stably present, the concentration in the buffer solution (pH 9.5 and pH 11.0) decreased with time, the degradation found pseudo-first order kinetics, RT-A the degradation half-lives were 3.76 and 0.30 h, and the RT-A detected after incubation in a phosphate buffer of pH 11.0, to a large number of RT-B. As the temperature increases, the RT-A decrease in stability, the half-life of the 0,25,34 and 50 ° C under conditions for 50.2,8.60,5.37 and 1.54 h, respectively. RT-A in the plasma is also extremely unstable, by adding inhibitors NaF enhances its stability in plasma. This article was first established the plasma samples RT-B HPLC method. Using the Kromasil C 18 column, acetonitrile -0.2% phosphoric acid solution (28:72, v / v) as the mobile phase flow rate of 1.0 mL / min, the detection wavelength was 318 nm, column temperature was 40 ° C. its linear range 0.04-10μg/mL (r = 0.999 4), intra-day and inter-day precision (RSD) were less than 15%, and accuracy (RE) in 4.7%. The method is simple, accurate, reproducible, and plasma samples RT-B provides a quantitative analysis method. RT-B in rat plasma protein binding rate was investigated by equilibrium dialysis, plasma concentration monitoring and clinical RT-B method. Preparation of low, medium, and high concentration of 3 drug-containing the dialysate (1,2 and 3μg/mL,), each concentration of 3 samples for analysis at the end of the 4,10,24 and 48 h, respectively experiment, the equilibrium time of the plasma protein dialysis were investigated, and 24 h for the final balance time. The results showed that low, middle and high concentration, the RT-B of the plasma protein binding rate (79.2 ± 0.7)%, (80.1 ± 0.9)% and (80.2 ± 0.9)%, RT-B mean plasma protein binding rate (79.8 ± 0.8)%.
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