Preparation Of Radiopaque Marker

Slow transit constipation is a common disease in the world and has high incidence.Colonic transit test is an important examination method to slow transit constipation,and it can be used to assess colonic transportation function,judge barrier to the transport site by the radioopaque markers.But the domestic manufacturers don’t deal in the radioopaque markers actively,which have given rise to the inconvenience of slow transit constipation diagnosis.Therefore,the development of an ideal radioopaque marker is necessary and important.This study aims to prepare barium sulfate coated pellets as radioopaque markers and determine its quality and the stability.In our study,the barium sulfate pellet core was prepared by extrusion-spheronisation.Taking friability,roundness and yield as indexes,the effects of process variables and formulation variables on pellets preparation were investigated.Orthogonal design were used to optimize the experiment conditions.The formulation and preparation process of barium sulfate pellets core were optimized.The centrifugal granulation and powder layering techniques were applied to prepare barium sulfate pellets.We studied the influencing factors of prescription and process on the properties of the pellets based on the indexes of friability,roundness and yield.The preparation process of barium sulfate pellets could be optimized by response surface analysis.The barium sulfate pellets were coated by fluidized bed bottom spray coating technology.EC was used as coating material.The formulation and technology of barium sulfate coated pellets were selected by signal factor and orthogonal experiments.The optimal formulation was validated.We evaluated its quality and stability preliminarily.We finally established a rat model of slow transit constipation,and observed the transmission of barium sulfate coated pellets as radioopaque markers in this model.It was proved that the barium sulfate coated pellets are beneficial to diagnose slow transit constipation in rats.Above results demonstrate that the established formulation and process are reproducible to prepare barium sulfate coated pellets as radioopaque markers with good stability,and the coated pellets are visualizing clear.The barium sulfate coated pellets can be used as radioopaque markers for examining colonic transit function successfully.