Vitro Release Of Rifampicin Alginate Microspheres Embolization Agent Nature Of The Study

Objective:Study on the rifampicin sodium alginate microsphere embolization agent in vitro release in different conditions and the agent's drug content, stability, degradation to make preliminary evaluation on the agent and provide reference for the clinical tests and applications.Methods:To observe the surface and the inner structure of the alginate microsphere embolization agent by scanning electronic microscope (SEM ).The drug content, stability and degradation were analyzed by High Performance Liquid Chromatography(HPLC);Placed the rifampicin sodium alginate microspheres in release medium of different concentrations of BSA and different volume and in different rotation speed to observe and study the agent's release behavior ;Besides,we also research on the agent degradation in the release medium.Results:The results of SEM show that the alginate microsphere embolization agent is rough and has irregular protrusions in its surface and loose and porous in its internal structure.The optimization result of HPLC is to adjust the proportion of mobile phase to methanol:acetonitrile:0.075mol/L potassium dihydrogen phosphate:1.0mol/Lcitric acid(30:32:36:4),column temperature 35℃.The test result of drug content shows that the drug content of low-dosage(100±10 mg/g),mid-dosage (200±10 mg/g)and high-dosage (400±10 mg/g) agent are 178.7024±9.0310mg/g,282.8304±5.3136 mg/g,387.6569±15.5793 mg/g respectively。The test result of in vitro release shows that maximum cumulative release increases with the increase of the BSA concentration and the volume of release medium and the rotation speed, but the difference of maximum cumulative release in 10mL release medium and in 30mL and 50mL release medium is great.Rifampicin reference substance has the same degradation in release medium which has the different BSA concentration and in different rotation speed.The degradation speed influenced by the volume of release medium,it accelerates with the volume increase .Conclusion:SEM shows that the rough surface and the internal pore structure of the microparticles which is helpful to the drug release by the dissolution medium permeation; the drug content of the high dosage group samples is conformed with the labelled amount,while the low-dosage and the mid-dosage group are far from the standard content; the microparticles in vitro release are influenced by the concentration of the BSA in the release medium and the volume of the release mediμm and the rotation speed.But,overall, it has sustained release performance .