The release k t of the hydrophobic DTXL and its conjugates from a hydrophobic polymer matrix into an aqueous solution can be described via a diffusivity-solubility model, which is commonly used to predict the permeation of hydrophobic drugs across membranes. Similarly, 𝑘 # would mostly depend on the free energy of translocation variation, Δ𝐺 # * , between the preferred location of the drug (inside the matrix or at the matrix-water interface) and the reference value in the aqueous solution and, less extensively, on the diffusion coefficient 𝐷 of the drug according to: 17