PROBLEM TO BE SOLVED: To provide a novel drug delivery system including a magnetic carrier based on an organic compound. A drug delivery system composition for delivering a drug to a target tissue while allowing the target tissue to survive, the composition including a structure of a metal halide acene complex or a metal acene complex dimer as a magnetic carrier. [Selection diagram] Figure 1【課題】有機化合物ベースの磁性担体を含む新規な薬剤送達システムを提供する。【解決手段】標的組織を生存させながら標的組織に薬剤を送達するための薬剤送達システム組成物であって、ハロゲン化金属アセン錯体または金属アセン錯体二量体の構造を磁性担体として含む組成物。【選択図】図1