ABSTRACT
<p><b>OBJECTIVE</b>To study the possibility of hyaluronic acid as densifier of Shuanguangliao eye-drops.</p><p><b>METHOD</b>The factors related with hyaluronic acid s viscosity, such as pH-value and storing temperature, are tested in this experiment. At the same time, we checked the stimulation, stability of the densifier.</p><p><b>RESULT</b>There was not effect on viscosity of pH-value and storing temperature. No stimulation on the eye was found after densified with hyaluronic acid. The viscosity properties of hyaluronic acid are stablile.</p><p><b>CONCLUSION</b>The hyaliuronic acid added to Shuanghuanglian eye-drops are stabiliable and it can be applied in eye-drops. The increased viscosity is benefit to extend the residence time of drug in eye.</p>