Objective To establish a method for the determination of residual solvents in tulobuterol by GC and optimize the purified process of crude tulobuterol product by this method. Methods The analysis was performed on Agilent DB-624 capillary column (30 m×0.32 mm,1.8 μm).The carrier gas was nitrogen at 1 mL·min-1.The injector temperature was 250 ℃.Detector was FID with hydrogen at 45 mL·min-1and air at 450 mL·min-1.The detector temperature was 250 ℃.The column temperature program was used.And the flow ratio was 10:1.Dimethyl sulfoxide (DMSO) was used as solvent of reference and test solution. Results Ethanol,tert-butylamine,dichloromethane,tert-butyl-methyl ether,n-hexane and 1,4-dioxane were completely separated.The calibration curve of each solvent showed good linear correlation. The RSD of precision was less than 5.0% and the average recovery ranged from 97.0% to 104.0% (RSD<5%).By optimizing the purification process of toloterol,the residue of organic solvent in the preparation of tolobuterol was in accordance with the Chinese Pharmacopoeia ( 2015) limit. Conclusion Validated by methodology,this simple,rapid and precise method can be used for the test of residual solvents in tulobuterol.

Objective In order to solve the obvious adverse reactions of ribavirin, to develop ribavirin liposome inhalation powder and to evaluate its quality characteristics. Methods The ribavirin liposomes were prepared by the thin film dispersion method, and then lyophilized to prepare ribavirin liposome powder. The appearance, fluidity, bulk density, encapsulation efficiency, particle size of the complex solution, PDI, potential and hydrophilicity were examined. Results Ribavirin liposome powder has good morphology, particle size, potential, fluidity and hydrophilicity, which can meet the basic requirements of powder medicine for drug administration. Conclusion The technique of preparing ribavirin liposome powder aerosol preparation by this method is feasible, and it provides the basic technology for future in vivo and in vitro studies.