To provide shows the release rate was remarkably similar in the entire GI tract, regardless of the pH of the environment, the sustained-release formulation of once-daily administration of lamotrigine (lamothgine). The formulations, including lamotrigine, an organic acid, a controlled release polymer and release promoting polymer. I also discloses use of the formulation for the treatment of neurological disorders. [Selection] Figure Figure 1環境のpHと関係なくGI管全体で著しく類似した放出速度を示す、ラモトリジン(lamothgine)の1日1回投与の持続放出製剤を提供する。本製剤は、ラモトリジン、有機酸、放出促進ポリマー及び放出制御ポリマーを含む。神経学的障害を治療する製剤の使用も開示する。【選択図】図1