To study the effect of CCBu concentrations on the model membranes systems involving 5, 10, 15, 20, 30, 40 and 50 CCBu in E-conformation have been constructed. Afterwards, steered MD (SMD) was performed to pull all molecules separately inside the lipid bilayer from the water bulk by applying a harmonic force of 10 kcal/mol over 200 000 steps with timestep of 4 fs. The center of mass of each CCBu molecule and the center of the membrane were used as collective variables. We note that each molecule has reached the lipid core without causing the rupture of the membrane. After SDM, unconstrained equilibrium MD simulations (650-1200 ns) has been run to assure the equilibration of the whole system.