ABSTRACTThe present invention provides a therapeutic or preventive agent for hypertension or normal high blood pressure, and for renal dysfuncti.on, 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-phenylthiatole compound represented by the following formula (I)[Chemical Formula 1][err]or a pharmaceutically acceptable salt thereof.