Preparation Of Azithromycin Solid Dispersion

Solid dispersion technology is employed to increase solubility and dissolution of water-insoluble azithromycin. Bioavailability is improved by change of the existing form including granularity and crystalline form, which is beneficial to reduce dosage of clinical use, toxicity and side effect.Through dissolution test, preparation technology and formulation are screened. The final formulation and preparation technology are obtained. The optimal formula- teon: azithromycin 1 g, CrosPVP 3 g, anhydrous alcohol 70 mL. The optimal prepar- ation technology: Azithromycin is dissolved in anhydrous alcohol with magnetic force mixing and then CrosPVP is added into the alcohol solution. After stirring for 60 min at a medium speed,ethonal is removed using rotating evaporator at a reduced pressure and the solid is desiccated for 24 h in drying cabinet at 50℃. The product is ground, sieved by 80 mesh and preserved in desiccator avoiding light.Quality inspection is conducted and following results is obtained: Azithromycin is mainly absorpted to the surface and cavity of CrosPVP as amorphous state. The solid dispersion is prone to absorb moisture and should be conserved under dried conditions. Good stability is showed by stability test and also CrosPVP is a promising carrier in solid dispersion technology.The drug release kinetics in vitro of the solid dispersion is studied. Accumulated dissolution of azithromycin is about 61.7% in 90 min. The release profile closely conformes to Higuchi model. The dissolution, content and content uniformity of the direct compression tablet of solid dispersion are proved to meet the specification.