Study On Compound Roxithromycin Sustained-Release Pellets

In this study, sustained-release pellets containing Roxithromycin and Ambroxol HCl were prepared. The sustained-release pellets were coated by the polymer (Eudragit NE30D), and the coating formulation and process were optimized. The relative bioavailability of the pellets to the commercial preparation were inverstigated in heathy dogs. The results show: the sustained-release pellets exhibited a marked sustained-release property .In the preformulation researches, the physicochemical properties of Roxithromycin and Ambroxol HCl were investigated, which benefitted pharmaceutical design. Reversed-phase HPLC method was established for determination of Roxithromycin content in pellets, while UV spectrophoto-meter was employed for determining Ambroxol HCl content. In the study of bioavailability, HPLC was applied to determine the plasma concentrations of Roxithromycin and Ambroxol HCl in dogs.The study of in situ intestinal absorption in rat showed that the absorption mechanism of Ambroxol HCl is passive diffusion without the effect of bile and other excretory products. There was no significant difference about absorption rate from various intestinal segments.A single-factor design was employed to isolate critical parameters that influenced the yield of pellets prepared by extrusion-spheronization method. It was found that spheronization speed, spheronization time and extrusion speed had great influences on the yield of pellets. Then, 3~3 full factorical design had been used to investigate the main effects and their interactive of extrusion speed, spheronization speed and spheronization time on the yield and...