However, the drawback of such an approach as reported previously in unmodulated structures resulted in the lowering of the loading capacity as well. We addressed this limitation by introducing a double layer system consisting of a top layer of reduced diameter, which minimizes the burst release and subsequently opens into a bottom layer with a larger tube diameter for optimal storage of drug, wherein additional loading into this layer is propelled due to pressure differences within the adjoining capillaries. A summarized representation of these results is shown in table 2. We achieved a maximized loading capacity whilst lowering the burst release and subsequently prolonging the reten-tion within such nanotubes via this double layer modification, rather than by reducing the diameter along the entire length of the nanotube. This is a viable solution to minimizing the burst release while not compromising the loading efficiency. The initial release for M 1 -ZrNT was higher at 40 % compared to H -ZrNT; but a close examination of the release curve shows stabilization of drug release after the 4 th hour, which is not observable in H -ZrNT and ultimately, the release from H -ZrNT was higher after 3 days at 61 %, when compared to 43 % for M 1 -ZrNT and 16 % for M 2 -ZrNT. This stabilization may be attributed to an increased influence of the bottle neck between the first and second layer in the modulated structure in the controlling the flow of drug. The time required for the drug to completely elute varies for the different structures, 14 days for H -ZrNT and a delayed time of 34 days for M 2 -ZrNT. The differences in release time for the modulated structures (15 and 34 days for M 1 -ZrNT and M 2 -ZrNT respectively) can be due to the length of the first layer which increased from 2 µm to 7 µm this implies that it will take a much longer time for drug loaded in the second layer to elute from the nanotube, attributed to a longer diffusion path length. The release of therapeutics at a suitable dosage over a long period is a critical factor in integrating nanotubular coatings in orthopedic applications and various strategies have been investigated to achieve an extended zero-order kinetic release of drugs. However, in this paper, we have successfully shown a proof-of-concept, that an extended-release of drugs can be achieved by simple structural modification of metal-oxide nanostructures.