Preparation Of FSH And SCF Microspheres And Sustained Released Study In Vitro And In Vivo

[Objective] To prepare PLGA microspheres containing follicle stimulating hormone(FSH) and stem cell factor(SCF) and investigate quality parameters.To study the influence factors of microsphere size and encapsulation efficiency. Further more, to observe the effects of sustaining release in vitro and in vivo.[Methods] FSH and SCF microspheres were prepared by a double-emulsification solvent evaporation method with PLGA which was biodegradable polymer as carrier material and were observed morphology with electron microscopy and were calculated some parameters such as particle size, encapsulation efficiency, drug loading, etc. Microspheres were prepared with different molecular weight and concentration of PLGA to observe the changes about particle size and encapsulation efficiency. Releasing experiments in vitro and in vivo were tested through culture and intramuscular method. Specimens were taken at fixed point and the drug concentration was measured by chemiluminescence or enzyme-linked immunosorbent assay. Concentration-time curve was drawn at last.[Results] FSH and SCF-loaded microspheres were rules spherical and good dispersion. The particle size showed a normal distribution and the diameters were mainly between 6μm and 12μm. The encapsulation efficiency and drug loading about FSH were 86.5% and 33.7mIU/mg, that about SCF were 89.1% and 4.7ng/mg.With PLGA molecular weight increased, increasing in microsphere size. Particle size and encapsulation efficiency of microspheres also increased when PLGA concentration increased.FSH and SCF microspheres sustained more than 28 days in vitro release, the cumulative release rate was 83.2% and 91.6% respectively,sustained-release curve was fitted Higuchi equation. In vivo, the drug concentration reached peak after the burst release of FSH and SCF microspheres and which was followed by the slow decline and that maintained a high level up to 17 days.[Conclusion] This technique of double emulsion-solvent evaporation process was simple and had a good reproducibility. FSH and SCF microspheres had uniform particle size,high encapsulation efficiency, good release effect in vitro and in vivo. The drug microspheres were expected to be used for the animal model of non-obstructive azoospermia.