The Research Of Water-soluble Drug Microencapsulation And Release Characteristic

The advance of the application and the existent problem of the microencapsulation technology were summarized in the article.And the core ,the wall-materials and the preparation technics of the microcapsules were discussed.Since the microencapsulation was initiated in 1957,the drug-microencapsulation are attracting the attention of pharmaceutical circle. The microcapsules can change the appearance and the property of the material,prolong and control drug release rate and improve the storage stability of the drug.The microencapsulation technology has been widely used in the biology and pharmacy field.One of the prominent application is the controlled release of the drug.Microcapsules can make drug release slowly .Compared to the research of the microencapsulation of the oil solubility drug ,the water solubility drug is less.The experiment made use of the low-release capability of the microcapsule ,discussed the preparation and the property of the water solubility drug microcapsule.The results gives certain theory-base for the microcapsule preparation of the water solubility drug.The glycyrrhizic acid was choosed as the core and two methods were took..One is oil-liquid drying method,the other is the organic solvent evaporation method.The effect of stirring speed and time,the wall-materail concentration and the emugent concentration were considered.In the first method,glutin was choosed as the wall-material ,but in the second method was ethylcellulose .The suitable method can be choosed by the comparison of the release property of the two kinds of microcapsules.The experiement found that the glutin microcapsule released too quickly. But the ethylcellulose microcapsules possessed obvious low-release property,which were accord with the test request.In the preparation of the ethycellulose microcapsules,the effect of the stirring speed and the time,the concentration and the sort of the emulgent,the sort and the concentration of organic-solvents were considered.By the single-factor and the orthogonal test ,with the stirring speed of 1500r/min,10min ,the wall-material of 4%,the glutin of 1.5%,the evaporation temperature of 30 ,the smallest and the most uniformity microcapsules can be prepared.The mean diameter of the microcapsules was about 180um.The microcapsules which possessing low -release property can be producted by organic solvent evaporation method,The ethylcellulose microcapsules accorded with Higuchi model,which belong to the system of framework release.The result diacated that the water solubility-drug can be enveloped by organic solvent evaporation method and the low release effect was realized.