Preparation And Quality Standards The M. Dodecandrum Intragastric Floating Tablets

The herb Melastoma dodecandrum Lour. recorded in the Dictionary of Chinese Herbal Medicines has the effect of activating blood circulation and arresting bleeding. It has been commonly used for treatment of algomenrrhea,postpartum abdominalgia,profuse uterine bleeding,fluor,hemafecia,dysentery,anthracia and furunculosis.However, as a kind of ethnodrugs and used locally, the chemical compositions of Melastoma dodecandrum Lour.have not been studied systemically, and the active constituents have not been certificated neither. Literatures studies showed that tannins,steroids,saponins,flavonoids,lactones,alkaloids,amino acids and saccharides were identified from Melastoma dodecandrum Lour..It was reported by clinical studies that Melastoma dodecandrum Lour.had gained an significant effectiveness in the treatment of upper gastrointestinal hemorrhage in which tannins and phenols were considered as the active consitituents.Meanwhile, as the therapy of activating blood circulation and arresting bleeding was commonly used in the treatment of hemorrhage according to the theory of traditional Chinese medicine, flavonoids was also considered to play a role in the treatment of blood-stanching.Upper gastrointestinal hemorrhage, which was commonly accompanied with gastric mucosal lesion and recurrent bleeding, needs to be administered frequently in a considerable period. Gastric floating tablet is considered as a new kind drug delivery system. The gastric retention time of floating tablet whose specific density is smaller than water when expanding after hydrating and gelating could be increased, so that the drug absorption would be improved and biological availability be elevated.The total flavanoids,tannins and phenols were isolated and purified in the study and would be prepared into gastric floating tablet when their contents reached 50%. The methods of quality control were also studied to guarantee the safety and effectiveness of the herb and its preparations .The contents of total flavanoids,tannins and phenols in the Melastom dodecandrum Lour. was determined by ultraviolet spectrophotometry. As the results respectively 1.1575%,1.0901% and 3.0352% were too small to make a preparation, the macroporous resin was selected to enrich the consitituents. And the result showed that the content of phenols reached 50%. According to the study, the content of phenols (with quercetin combined with luteolin as control articles) was determined by ultraviolet spectrophotometry as a method of quality control. Furthermore,the contents of target constituents of phenols--galic acid and quercet- -in dertermined by HPLC was also added to the methods of quality control.The influential factors of macroporous resin in the isolation and purition of phenols from Melastoma dodecandrum Lour.:resin types,PH of loading solutions,concentrations of loading solutions,loading capacity,loading velocity,elution velocity,elution concentrations,elution volume,frequency of use of resin, etc ,were studied with the contents of phenols as evaluation. The HPD100 macroporous resin was found with the best separating efficiency when the PH 2.7-4.5 loading solution(0.2g /ml) passed the resin with a velocity of 3BV/h. Then the distilled water and 60% ethyl alcohol respectively 5BV were used in turns to pass the resin with a velocity of 3BV/h. The fraction of 60% ethyl alcohol was collected and evaporated to dryness.The phenols isolated and purified from Melastoma dodecandrum Lour.with macroporous resin were to be prepared into gastric floating tablet. The formulation and pressure of the preparation were evaluated by vitro floatation and releasing performance. The tablets were successfully prepared in which the phenols,EudragitⅣ,Octadecanol were 31% respectively, while MCC101 was 7%. And 3-4kg was found to be the eligible pressure. Meanwhile,as the residue and safety of the use of macropous resin has caught a lot of concerns, the content of beneze vinyl was determined by vapor phase chromatography(VPC) to certify the safety.In the study of quality specification, the target consitituents of phenols–galic acid and quercetin was studied by TLC and HPLC to guarantee the quality of the gastric floating tablet.