Methods and apparatus are disclosed for filling a therapeutic substance or drug within a hollow wire that forms a stent. The stent is placed within a chamber housing a fluid drug formulation. During filling, the chamber is maintained at or near the vapor-liquid equilibrium of the solvent of the fluid drug formulation. To fill the stent, at least a portion of the stent is placed into contact with the fluid drug formulation until a lumenal space defined by the hollow wire is at least partially filled with the fluid drug formulation via capillary action. After filling is complete, the stent is retracted such that the stent is no longer in contact with the fluid drug formulation. The solvent vapor pressure within the chamber is reduced to evaporate a solvent of the fluid drug formulation. A wicking means may control transfer of the fluid drug formulation into the stent.