Molecular dynamics simulations have been investigated to study the interactions between single-wall carbon nanotubes and an anticancer agent Pt complex (Cisplatin). The optimized diameter of the vector system has been determined to encapsulate in the best conditions the drug molecules. The simulation results show also that several drug molecules can be adsorbed inside the nanotubes, leading to an increased confinement time. Moreover, our simulations show that the release of the drug near a cell membrane model is favored, opening the way to a natural drug nanocapsule.