Table reports the data used in the previous report as well as the logPI app of the tested molecules picked up from experimental measurements from the literature when available; otherwise, this parameter was simulated using predictive software such as ChemAxon. The predicted n-octanol/water distribution coefficients for spiked drugs to pH = 6.8 using Eq. 2 (see Fig 7, right) improved the correlation by 4% and showed an improved linear regression between both descriptors (see the linear equations in Fig. ). In more detail, the improvement resides precisely in two compounds that had an experimental value of logPI app (ketoprofen and oxytetracycline). This observation highlights the importance of experimental measurements of ionic partitions but also calls for more experimental work focused on these issues, taking into account the scarce values available in the literature and the difficulty of finding them in public databases. Figure shows that the consideration of the apparent ionic partition significantly improved the correlation between the experimental and predicted values, where the RMSE decreased in 0.26 logD units, representing an appreciable improvement of 54 %. This application demonstrated that the thermodynamic equilibrium derived in Eq. 2 applies to partitions other than the n-octanol/water system, such as in the PDMS/water phases. The presence of some free silanol groups, combined with the highly hydrophobic polymeric chain might create a suitable environment for ionizedorganic species in the PDMS phase through a combination of hydrogen bonds from the terminal -OH groups and dispersion non-covalent forces from the polymeric chains. Finally, an important metric that has been increasingly applied in drug discovery and medicinal chemistry lead optimization endeavors is the lipophilic efficiency (LipE, see Eq. 6).