Abstract:Objective: To study the possibility of hyaluronic acid as densifier of Shuanguangliao eye-drops. Method: 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 Result: 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. Conclusion: 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.