ABSTRACT
<p><b>OBJECTIVE</b>To prepare OANO-1 microspheres and test their release in vitro.</p><p><b>METHOD</b>OANO-1 microspheres were made by W/O/W-liquid drying process. The surface morphology of the microspheres was observed by SEM. The mean diameter and the size distribution of microspheres, the drug loading and the incorporation efficiency were examined. The release of OANO-1 microspheres in vitro was examined by small cup method. The accumulated release percent of OANO-1 microspheres was examined.</p><p><b>RESULT</b>The OANO-1 microspheres were regular in their morphology. The average particle size was 8.59 microm with over 90% of the microspheres being in the range of 1-12 microm. The drug loading and the incorporation efficiency were 48.39% and 19.32% respectively. The accumulated release percent of OANO-1 microspheres was 78.4% after 108 h. The release half-life t1/2 was 40.8 h and Higuchi equation was Y = 0.1326 X - 0.4782, r = 0.9951.</p><p><b>CONCLUSION</b>The preparation of OANO-1 microspheres was well. The release in vitro of OANO-1 microspheres showed significant sustained release.</p>