In a diquafosol eye drop containing a chelating agent at a concentration of 0.0001 to 1% (w/v) the production of insoluble precipitates during storage which is usually observed in a diquafosol eye drop and the deterioration in filtering performane during a production process (a filter sterilization process) can be prevented. In a diquafosol eye drop containing a chelating agent the reduction in eye irritation and the improvement in preservative efficacy compared with those in a diquafosol eye drop that does not contain any chelating agent are observed. Therefore in the present invention stable physicochemical properties can be achieved during the course of production and distribution and during the course of storage by a patient and the reduction in eye irritation and the improvement in preservative efficacy are observed. Particularly in a diquafosol eye drop containing a chelating agent the deterioration in filtering performance during a production process (a filter sterilization process) is prevented. Therefore highly efficient filter sterilization can be achieved during the course of production which contributes to the reduction in production cost.
