Cimicifuga Quality Evaluation Methods And Pharmacokinetic Studies

The present study provides a method for the determination of caffeic, ferulic acid and isoferulic acid in Rhizoma Cimicifugae simultaneously by high performance liquid chromatography. Besides, high performance liquid chromatographic fingerprint chromatogram was established for the herb. The integrated quality assessment of Rhizoma Cimicifugae was developed. In this paper, a simple, specific and rapid HPLC method was described to determine isoferulic acid in rat plasma for the first time. Furthermore, we studied the proceeding of pharmacokinetics in rats which was provided a foundation for clinic.We established a method for the determination of caffeic, ferulic acid and isoferulic acid in Rhizoma Cimicifugae by RP-HPLC. The caffeic, ferulic acid and isoferulic acid in the 21 batches of Rhizoma Cimicifugae were analyzed. The chromatographic condition included a Kromasil C₁₈ (250 mm×4.6 mm i.d., 5μm) column and the mobile phase consisting of acetonitrile-water-phosphate acid (13: 87: 0.05) and the absorbance was monitored at 320 nm. The linear ranges for caffeic, ferulic acid and isoferulic acid were 2.66-26.6μg·mL^-1(r=0.999 5), 6-60μg·mL^-1(r=0.999 3)and 20.6-206μg.mL^-1(r=0.999 3), respectively. The average recoveries were 99.8ï¼…(RSD=1.5ï¼…), 98.2ï¼…(RSD=1.1ï¼…) and 101.0ï¼…(RSD=1.8ï¼…), respectively. The method is simple and accuracy with good reproducibility and suitable for measure the concentration of caffeic, ferulic acid and isoferulic acid in Rhizoma Cimicifugae. The method can be validly used to evaluate the quality of Rhizoma Cimicifugae.High performance liquid chromatographic fingerprint chromatogram was established for Rhizoma Cimicifugae. The chromatographic condition included a Kromasil C₁₈ (250 mm×4.6 mm i.d., 5μm) column, the gradient elution with acetonitrile and 0.05ï¼…phosphate acid solution. The detection wavelength was 320nm. 21 batches of Rhizoma Cimicifugae were studied under this condition. With the Between-groups linkage method and the Cosine used as the measurement index, the Hierarchical cluster was applied to the fingerprints of Rhizoma Cimicifugae and the 21 batches of Rhizoma Cimicifugae was divided into two grades. Among them the gradeâ… was commendatory and the gradeâ…¡was general. Mutual pattern was established from 17 batches in the gradeâ… . Similarity calculations were studied by comparing the HPLC fingerprint chromatograms of Rhizoma Cimicifugae and mutual pattern. The similarity by the Cosine, Pearson correlation and Euclidean distance, was calculated respectively. These results of the commendatory should be all over 0.90 and the other samples were the general. The method can be used as a quality control method for Rhizoma Cimicifugae.A simple and specific a high-performace liquid chromatography(HPLC) method with ultraviolet(UV) absorbance detection has been developed for the determination of isoferulic acid in rat plasma. The plasma samples were deproteinized with methanol after addition of internal standard (IS) tinidazole. The analysis was performed on a Kromasil C₁₈ column (250 mm×4.6mm i.d., 5μm) with acetonitrile-0.05ï¼…phosphoric acid (25:75,v/v) as mobile phase. The linear range was 20.6-5150 ng·mL^-1 and the lower limit of quantification (LLOQ) was 20.6 ng·mL^-1. The intra- and inter-day relative standard deviations (RSDï¼…) were less than 11.4ï¼…and 12.3ï¼…, respectively, and accuracy as relative error (REï¼…) was±6.7ï¼…. Mean extraction recovery was 81.9ï¼…. The plasma concentrations of isoferulic acid at different times were expressed as mean±SD and the mean concentration-time curve was plotted. Besides, we calculated the corresponding pharmacokinetic data. The results indicated that there were significant differences in pharmacokinetics parameters between the two preparations(isoferulic acid and Rhizoma Cimicifugae extract) of the same isoferulic acid dosage level. The Cmax of two preparations were 2.88μg mL^-1 and 1.58μg mL^-1 respectively. The 1.6-fold enhancements of AUC_0-t were observed from Rhizoma Cimicifugae extract compared with isoferulic acid at the same dosage of isoferulic acid. This was probably caused by the effect of the other constituents in Rhizoma Cimicifugae which may improve absorption of isoferulic acid from the gastrointestinal tract. The validated method was successfully applied to pharmacokinetic study of isoferulic acid in rat plasma after oral administration of isoferulic acid and Rhizoma Cimicifugae extract.