Studies On Qulity Control Of Reyanning Capsule And Pharmacokinetic Of Emodin

Reyanning capsule, consisted of Herba taraxaci, Rhizoma et radix polygoni cuspidate, Rhizoma seu Herba Patriniae, and Herba scutellariae barbatae, is one of traditional Chinese medicine recipe for clearing heat and detoxicating. In this dissertation, method of qulity control and the pharmacokinetics of emodin in different decoction were studied.RP-HPLC methods were established to determine chlorogenic acid and caffeic acid in Herba taraxaci, emodin in Rhizoma et radix polygoni cuspidate, oleanolic acid in Rhizoma seu Herba Patriniae,and scutellarein in Herba scutellariae barbatae in reyanning capsule. The determination could be accomplished by different mobile phase system in ODS columns. The linear ranges were 2.4-48.0μg·mL^-1 (r = 0.9995), 1.0-20.0μg·mL^-1 (r = 0.9997), 0.02-0.40μg·mL^-1 (r = 0.9999), 0.024-0.48μg·mL^-1 (r = 0.9997) and 6.96-139.2μg·mL^-1 (r = 0.9997), respectively. The recoveries were 99.7 % (RSD = 0.8 %), 100.8 % (RSD =1.1 %), 100.8 % (RSD = 1.8 %), 99.3 % (RSD = 1.2 %) and 100.1 % (RSD = 1.8 %), respectively. The assay methods are simple, rapid and with good reproducibility and provide a quantitative basis for the quality assessment for Reyanning capsule.The optimal ethanol extraction process of Reyanning was studied by orthogonal design with extractive yield and the contents of chlorogenic acid, caffeic acid, emodin, scutellarein, and oleanolic acid as indices. Three factors were studied in this experiment, including the concentration of ethanol, the solvent consumption, and times of extraction. The result showed that the optimal extracting condition was 70 % ethanol consummated ten times the amount of material, and two times for 1 hour each time.RP-HPLC methods were established to determine chlorogenic acid and caffeic acid from Herba taraxaci, emodin from Rhizoma et radix polygoni cuspidate, and scutellarein from Herba scutellariae barbatae in reyanning capsule. The determination could be accomplished by different mobile phase system in Diamonsil C₁₈ columns. The linear ranges were 1.7～34.0μg·mL^-1 (r=0.9995), 2.9～58.0μg·mL.(-1) (r=0.9997), 0.02～0.40 mg·mL(-1) (r=0.9999), and 6.96～139.2μg·mL^-1 (r=0.9997), respectively. The recoveries were 96.5% (RSD=2.5%), 99.5% (RSD=1.6%), 99.3% (RSD=2.0%), and 100.3% (RSD=1.8%), respectively. The contents were 0.395 mg.capsule^-1, 0.645 mg·capsule^-1, 1.41 mg·capsule^-1, 0.93 mg·capsule^-1, respectively. The assay methods are simple, rapid and with good reproducibility and provide a quantitative basis for the quality assessment for Reyanning capsule.Determination of emodin in rat plasma and tissues were applied to pharmacokinetic research by using HPLC-UV. The HPLC separation was achieved on a Diamonsil C₁₈ (200 mm×4.6 mm, 5μm, Dikma) column at 30℃. The mobile phase consisted of methanol- acetonitrile-0.1% phosphoric acid solution (27:50:23, v/v/v) at a flow rate of 1.0 mL·min^-1. The UV detection wavelength was set at 250 nm. The extraction recoveries exceeded 69.0%. Linear calibration plot was obtained in the concentration range from 0.0325 to 6.50μg·mL^-1(r＞0.996). Intra-day RSD and inter-day RSD were both less than 12%. The method is simple, special, accurate and reproducible.Emodin showed different pharmacokinetic characteristic in rat after intragastric administration of five different decoction, solution of dmodin, solution of decoction of Rhizoma et radix polygoni cuspidate, decoction of Rhizoma et radix polygoni cuspidate and decoction of Herba taraxaci, Rhizoma seu Herba Patriniae, and Herba scutellariae barbatae, decoction of the four crude herb, and Reyanning capsule. Emodin showed one-compartment model after intragastric administration of solution of dmodin, decoction of the four crude herb, and Reyanning capsule, and showed two-compartment model after intragastric administration of decoction of Rhizoma et radix polygoni cuspidate, decoction of Rhizoma et radix polygoni cuspidate and solution of decoction of Herba taraxaci, Rhizoma seu Herba Patriniae, and Herba scutellariae barbatae. After administration of emodin solution, t_1／2α was 3.7 h, t_1／2β was 5.6 h, Cmax was 0.60μg·mL^-1, AUC was 10.86μg·h·mL^-1. After administration of solution of decoction of Rhizoma et radix polygoni cuspidate, t_1／2α was 0.95 h, t_1／2β was 9.4 h, Cmax was 2.34μg·mL^-1, AUC was 22.10μg·h·mL^-1. After administration of decoction of Rhizoma et radix polygoni cuspidate and decoction of Herba taraxaci, Rhizoma seu Herba Patriniae, and Herba scutellariae barbatae, t_1／2α was 0.1 h, t_1/2β was 8.0 h, Cmax was 1.07μg·mL^-1, AUC was 8.45μg·h·mL^-1. After administration of decoction of the four crude herb, t_1／2αwas 0.3 h, h_1／2β was 16.4 h, Cmax was 0.51μg-mL^-1, AUC was 11.43μg·h·mL^-1. After administration of Reyanning capsule, t_1/2α was 0.1 h, t_1/2β was 4.0 h, Cmax was 0.60μg·mL^-1, AUC was 6.08μg·h·mL^-1.Emodin showed a quick distribution into tissue in rat after intragastric administration of decoction of Rhizoma et radix polygoni cuspidate and Reyanning capsule. Emodin mainly exists in stomach, small intestine, and large intestine. Then, emodin distributed in liver, kidney, spleen and lung. But there were little in heart, brain and plasma. The content of emodin in most tissues decreased gradually with the time lasting except large intestine with a peak at 8h. Except for this, there was a peak at 1h in kidney and lung after intragastric administration of Reyanning capsule.