Studies On Preparation Of Sustained-Release Dosage Forms With Watersoluble Drugs

A research on preparation of sustained-release pellets with watersoluble small-molecule drug was made in this study .It was a problem to prepare watersoluble drugs into sustained-release dosage,especially the preparation of watersoluble small-molecule drug . Potassium citrate was chosen as the model drug considering its academic and economic value .There is no Potassium citrate sustained-release dosages appearing on domestic market up to now.Ultraviolet spectrophotometric method was determined to measure the content of Potassium citrate in Potassium citrate sustained-release pellets,according that citrate and Cu²⁺ can complex into a complexing compound. Potassium citrate waxiness matrix pellets, Potassium citrate insoluble matrix pellets, Potassium citrate gel matrix pellets were prepared by the waxiness matrix material Hydrogenated castorseed oil,the insoluble matrix material ethylcellulose(EC), gel matrix material hydroxypropy methycellulose(HPMC),and their dissolution mechanisms were analysised in the article.The formulation and technics factors influencing the dissolution of different type pellets were discussed ,such as the type and amout of supplementary materials and lubricant, pressure , granule partical size,dissolution medium,rotation and so on.The size and shape of gel pellets were also discussed in the making-process of gel pellets.The formulation and technic were optimized through single factor experiments and orthogonal design.Gel matrix technic was confirmed to be the best technic according to its good reproductivity,and the best foumulation was determined by orthogonal design.The quality and stability were also examined in the exeperiments. The best formulation got in the experiments is as follows:Potassium citrate 1080mgHPMC 650mgMagnesium_<sub><sub><sub><sub><sub><sub><sub><sub>3%Total weight: 1782mg...