Figure 6.

QCM-D data for the 7.2 nm sample, displaying the different stages of ALN adsorption and release.

Notes: In (1), the adsorption kinetics is the rate-limiting factor. In (2), the rate-limiting factor of the adsorption is the diffusion factor. Between (2) and (3), the flow is changed to the rinsing flow, and the initial release (3) is determined by the molecular diffusion. The release becomes thereafter sustained (4) and the rate-limiting step is then the desorption isotherm.

Abbreviations: ALN, alendronate; QCM-D, quartz crystal microbalance with dissipation.