Study On The Purification Technology Of Thsg From The Root Of Polygonum Multiflorum Thunb And Preparation Of Its Microcapsules

THSG(2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside)is a typical functional component found in the root of Polygonum Multiflorum Thunb, contributed markedly both antiaging and to reducing serum lipids and to protecting liver, and so on. It was to be separated and purificated from the root of Polygonum Multiflorum Thunb. With what sustained release microcapsules were developed.This paper was to combine the supersonic with the extracting technology of THSG from PMT, by method of single-factor tests and the orthogonal tests. What were covered in this investigation, included concentration of THSG by macroporous adsorption resin and purification by silica gel column.The results showed that, the better extracting technology of THSG was as follows:the PMT particle of 150 mesh size; 60% edible alcohol of extracting solvent; 1:60 of PMT powder to edible alcohol ratio; 7 min of extracting time. The better separating condition of THSG turned out to be that:The macroporous adsorption resin column was eluted to remove pernicious impurities with large water, and 10% edible alcohol, then, THSG was eluted with 10% edible alcohol. High-Purity final product was obtained by silica gel column which was eluted with the mobile phase, petroleum ether:Ethyl Acetate=1:2, and then petroleum ether: Ethyl Acetate= 1:4.In the preparation of the ethy cellulose microcapsules, the effect on entrapment efficiency and drug loading of the ratio of oil-water volumes, the concentration of Span-80 and ethy cellulose, and the proportion of core material to wall material were tested. With encapsulation efficiency of more than 90% and drug loading about 50%, the optimized conditions were obtained.This powder-microcapsules can be used as intermediate in other pharmaceutical preparations. Then, it was mixed with the Sodium Alginate solution to make EC- Calcium Alginate microcapsules. Various factors of influence on microcapsules performance were considered. The result indicated that it releases the drug slowly for 30 hours in the phosphate buffer solution (pH=6.8). The process In vitro release could be expressed by Weibull model, and is coordination of diffusion and bulk erosion.THSG microcapsules were prepared by above optimium conditions. Research results revealed that EC-microcapsules were possessed encapsulation efficiency of 95.98%, and because more THSG dissolved in the solvent for its strong hydrophilicity, EC-Calcium Alginate microcapsules possessed lower encapsulation efficiency of 61.82%. In the phosphate buffer solution (pH=6.8) 30% of THSG was released in 8 hours slowly, and then the accumulated release rate decreased, this possibly due to the chang of ultraviolet absorption, which because Hydroxyl in THSG bonded with Carboxyl in Citric Acid.