Preparation Of Rhubarb Total Anthraquinones Oral Colon-Specific Drug Delivery Granule And Study On The Renal Toxicity Of It

Rhubarb is one of Traditiona Chinese Medicine.The most common use is its purgative effect. Anthraquinones in rhubarb are the effective components for purging. It is reported that anthraquinones in rhubarb had a certain degree of renal toxicity. This research is based on one of the mechanism of action of purgative effect of anthraquinones. The free-anthraquinones stimulate colon intine to play purgative effect in colon. The oral colon-specific delivery system of total anthraquinones in rhubarb will be prepared to avoid the renal toxicity caused by the adsorption of anthraquinones at upper digestive tract. The renal toxicity problem of anthraquinones was resolved radically. It is a new break through for chinese medicine attenuation by traditional processing and compatibility. There isn’t worry about of the renal toxicity when the colon-specific particles instead of the herb play purgative effects. It removes obstacles for the applications of rhubarb.There were four sections in this thesis.The first part:The establishment of analysis method in vitro on Rhubarb total anthraquinonesObjective:To establish a method for determination of extractive、RTA-OCDD-GN and in vitro release medium on Rhubarb total anthraquinones.Methods:Use the method of reversed phase high performance liquid chromatography. The HPLC separation was performed on a Diamonsil C18 analytical column, mobile phase with methanol-0.1%HC104 (85:15), detection wavelength was 254nm, at the flow rate of 1.0 mL·min-1, the temperature of column was 30℃. Mobile phase is methanol-1.1%HClO4 (80:20) and other conditions are the same in vitro release medium.Results:Anthraquinones chromatographic peak of resolution is good, excipients and release medium have not interference on determination. A good linearity of anthraquinones was obtained within the range of 0.36039～36.039μg/mL.Conclusion:The method was sensitive, simple and selective, and was applicable to the determination of RTA in vitro.The second part:Preparation of Rhubarb total anthraquinones oral colon-specific drug delivery granule.Objective:To prepare the RTA-OCDD-GN by choosing the right methods, and make them pass through the upper gastrointestinal tract saftely, and then release in the colon-specific.Method:Prepare the immediate-released particles by adding adjuvant with free-anthraquinones that its content should be more than 50%. Coating the controlled membrane in fluidized bed by bottom discharge. The experiment in vitro release is achieved by building model to the PH and physiological environment of stomach, small intestine and colon. Release rate is the standard of the prescription sieving, it joint with release the curve similarity analysis method to evaluation process technology of the feasibility and stability. Two factors three factorial experiment design level determine the best coating prescription.Result:Prepare colon-specific particles of total free -anthraquinones after the immediate-released particles being coated with enzyme-controlled and pH-sensitive materal. In the artificial gastric juice and artificial small intestine fluid, granule accumulative release 6.8% in 6 h. In artificial visualizing(RCM), granule accumulative release 87% in 6 h.Conclusion:Prepare colon-specific particles of total free-anthraquinones after the immediate-released particles being coated with enzyme-controlled and pH-sensitive materal.At present has achieved the good effect of colon-specific drug. The method is simple and reproducible.The third part:Study on the Rat’s renal toxicity of the Rheum and RTA-OCDD-GNObjective:To evaluate the difference between the Rheum and RTA-OCDD-GN on the Rat’s renal toxicity.Method:To test the purging of the the Rheum and RTA-OCDD-GN.The rats were randomly divided into different groups, one was RTA-OCDD-GN group, another was the Rheum group, and the last was control group. All the groups were administered intragastrically once daily for 40 days. After administration for 20,40, days and convalescence, killed the 1/3 of them, detect the blood biochemical indicator,β2-MG, urine routine and Histopathological examination. Then do statistic analyze.Result:1 The Rheum was administered to rats at oral doses of 0.66,0.33, 0.165g·kg-1·-1 once daily for 40 days. And the RTA-OCDD-GN was 0.526, 0.263,0.132g/kg/d.2 Rheum group:After 40 days of administration, blood chemical tests revealed that there was significant difference between the high-dose group and the control group on UREA and Crea. Urinalysis test results showed that urine β2-MG, BIL, PRO, KET, LEU, GLU, NIT etc, were significantly increased. In the low-dose group, ALT and URO were significantly increased. Histopathological examination showed that there were different degrees of tumefaction and degeneration on epithelia cells of proximal convoluted renal tubule of high-dose group sacrificed on 40 days. Withdrawal 20 d, each index of the high and medium dose group was restored. Well the URO, BIL LEU, NIT of the low-dose group were significantly increased still compared to the control group.3 There was no obvious difference in the indicators between RTA-OCDD-GN group and blank group, but the urine routine.Conclusion:In these conditions, the Rheum had toxicity to the kidney (esp. the proximal tubules), the toxicity was reversible. But there is different to the literature in the low does group. Every indicator increased significantly. There was tumefaction at proximal convoluted renal tubule, there was no toxicity when taked colon-specific particles orally.The renal toxicity of anthraquinones will be reduced obviously when prepared to colon-specific particles.The fourth part:Situation of RTA constituents in rat serum following intragastric administration of Rheum and RTA-OCDD-GN.Objective:To observe the differences of the constituents between Rheum and RTA-OCDD-GN absorbed into rat serum after oral asministration by the experiment of pharmacokinetics.Method:Establish in vivo analytical method of Rhubarb total anthraquinones.Divide the rats into two groups at random, one group was given RTA-OCDD-GN, the other Rheum.Collect the blood at the designated time.Detect the blood concentration of anthraquinones, count the average of Tmax、Cmax of the two groups by the blood concentration in different times and compare the discrepabcy of pharmacokinetics.Result:In 5h the weak absorption peak of rheinoside was recorded from the blood of RTA-OCDD-GN group, Tmax was 6h, Cmax was 0.41μg/mL, in Rhubarb extract, Tmax was 15min, Cmax was 4.7μg/mL. At other times the absorption peak of rheinoside was recorded.In 15min the weak absorption peak of Aloe-emodinrhien Emodin Chrysophanol Physcion was recorded.The other anthraquinones absorption peak were not recorded from the blood of the two groups.Conclusion:The effect of colon-specific delivery was achieved in rats in vivo.The blood concentration of rhein was lower than Rhubarb extract group, that may be the colon-specific granule and Rhubarb extract have different effects on kidey.