Study On Preparation Of Microcapsules And Microspheres Of Drugs By Spray Drying

Two drugs, the small molecule and soluble and the high molecule insoluble, with entirely different characteristics were chosen as model drugs. The prescriptions of microcapsules and microspheres for soluble and insoluble drugs were made respectively, which are significant for making microcapsules and microspheres with spray drying technique in theory. Using the spray-drying equipment, the quantitative parameters were chosen including the inlet air temperature, the outlet air temperature, the feed flow rate and the spray pressure, which provides the theoretic data for similar spray-drying equipments in batch production. The quantification control for microcapsules and microspheres can insure the quality of the preparation to solve the difficult problems of instability of this kind of preparation in production.The small molecule and soluble drug, Metformin Hydrochloride as a model drug, was prepared to sustained-release microspheres by spray-drying technology. The formulation factors as types and amount of Eudragit(a crylic acid polymer), plasticizers,antiadhesives were studied. Some key operational parameters,such as the inlet air temPerature,the outlet air temperature, the feed flow rate and the spray pressure etc were determined to some extent by the single factor analysis.Further more,the optimum condition of spray-drying is achieved by orthogonal experiment,including inlet air temperature of 165℃,the feed flow rate of 10mL·min-1 and the spray pressure of 0.5MPa. In the conditions the encapsulated efficiency of microspheres reaches 94%. The optimum process and formulation of Metformin Hydrochloride sustained-release microspheres with spray-drying technology was determined, which meets the design demand. Three batches of tablets were prepared by optimized formulation and process to examine the repetition of the prescription and the process. And the basic stability of the tablets was also carried out. the conditions of drug release in vitro such as particle diameter, rotate speed of bascket were researched for the effects on coating and drug release.By changing the ratio of Eudragit L100 and S100 we obtained the prescription which release percent meets standard basically.The high molecule and insoluble drug, dextrin as a model drug was prepared to enteric microcapsules by spray-drying technology. First by studying types of Eudragit and the feed flow rate, Eudragit L100 was choosed for material of microcapsules and the feed flow rate were determined to 10～20 mL·min-1. Further more,the optimum condition of spray-drying is achieved by orthogonal experiment,including Eudragit amount of 5%,ratio of dextrin and Eudragit L100 of 1:3, inlet air temperature of 165℃, and the spray pressure of 0.45MPa. In the conditions the encapsulated efficiency of microcapsules reaches about 85%. The partical size distribution, plane critical angle, angle of repose, density of microcapsules ,moisture and the test of microcapsules are used to evaluate the quality of the microcapsules.By testing the release degree in vitro, the drug released was more than 90% in 100min, So the release rate of microcapsules in artificial intestinal juice was quickly.Bacterin of Vibrio anguillarum was prepared to microcapsules using the optimum process and formulation of dextrin microcapsules. Comparision of bacterioiytic activity, the concentration of protein in Paralichthys olivaceus serums, Serums antibody levels and relative Percent Survival(RPS) after challenged were tested using Paralichthys olivaceus.As resulted, the Serums antibody levels and relative Percent Survival(RPS) after challenged of microcapsules were higher than bacterin of Vibrio anguillarum.So, the microcapsules Vibrio anguillarum were effective.The spray drying technology is simple,reliable and lower in costs for preparing microcapsules and microspheres,and can be used in big batches.so the practical meaning is important.