The present invention provides a therapeutic or preventive agent for hypertension or normal high blood pressure, and for renal dysfunction, that is more effective than existing drugs. More specifically, the present invention provides a sustained-release pharmaceutical composition for treating or preventing hypertension or normal high blood pressure, and for renal dysfunction, comprising as an active ingredient a 2-phenylthiazole compound represented by the following formula (I) [Chemical Formula 1] (I) or a pharmaceutically acceptable salt thereof.
