An aqueous eye drop comprising 2-amino-3-(4-bromobenzoyl)phenylacetic acid or its pharmacologically acceptable salt or a hydrate thereof and an organic amine (for example, aminoethylsulfonic acid or trometamol) or a salt thereof is useful as an eye drop for once a day administration for treating inflammatory diseases of the external segment or the anterior segment of the eyes, since such aqueous eye drop can maintain a therapeutically effective concentration of 2-amino-3-(4-bromobenzoyl)phenylacetic acid in anterior aqueous humor for at least 24 hours by once a day administration.
