Preparation Of Colon Targeted Rhubarb Capsule And Its Quality Evaluation

Colon site-specific drug delivery system, mainly including time-controlled release and pH-dependent form as well as bacterial-triggered form, is being extensively investigated in the pharmaceutical area. The technique of drug transfer is used in Oral Colon-targeting Drug Delivery System (OCDDS),in which drugs does not release in the upper digestive tract with oral administration but begins to collapse or erode when they arrive at ileocecus and act medicinally at colon. Aiming at Colon constipation, we researched on Rhubarb, which is an effective cure for Colon constipation in clinical use. We have got one colonic targeting preparation after research: pH-dependent drug delivery systems.According to the property of the medicinal material we extract Rhubarb with ethanol and screened out the best process to extract.,that is six times the amount of 60% ethanol 3rd 2 hours each; Considering the cost and safety of licorice extraction, the orthogonal test was designed, the final extraction process to determine the optimum conditions uses 12 times water heating to boiling with 2 times 2 hours each. We also established the quality standard of the extraction, Sennoside A was determined by HPLC, with a chromatography of C 1 8 column(5μm, 250×4.6 mm)and a mobile phase of Acetonitrile -0.05%PBS at 18:82(V/V),imperatorin is detected at a range of 271 nm.Study shows that the standard curve of imperatorin presents a fine linear relationship within the quality range of 0.1～2.0μg ; HPLC was used in the determination of Glycyrrhizin, with a chromatography of C 1 8 column(5μm, 250×4.6 mm)and a mobile phase of Methanol-Ammonium acetate(0.2M)- Acetic acid at 67:33:1.2(V/V), imperatorin is detected at a range of 254 nm.Study shows that the standard curve of imperatorin presents a fine linear relationship within the quality range of 0.1～2.0μg ; Study shows that the standard curve of imperatorin presents a fine linear relationship within the concentration range of 4～30 mg·mL^-1.By the experiments of simulating gastrointestinal tact environment in vitro and pharmacodynamics on rats comparing administration with clysters and OCDDS way, it is proved that components in common preparation of Rhubarb are demolished in gastrointestinal tract and not able to arrive at colon in integrity with oral administration. While colon targeted Rhubarb compound capsules in stomach and small intestine have a good tolerance, 2 h in the stomach and small intestine within 3 h of drug active ingredients basic no losses, at different pH artificial colon fluid in the 2 h, the release of drugs could exert better cure function.The Rhubarb extraction is prepared into Particles, after the screen-out experiments on preparing process. pH-dependent drug delivery systems have been studied. We evaluated the preparation in vitro and in vivo, which turned out that each is able to be colonic targeting.