In Vitro ADME

       Water solubility is a very important physicochemical parameter of a compound, which can reflect its bioavailability. Determining the solubility of compounds plays a key role in predicting drug absorption in the gastrointestinal tract, accurate in vitro bioanalysis, and selecting appropriate dosage forms for in vivo experiments. Therefore, compound solubility test at the drug discovery stage is very important for the subsequent development of compounds. Since most of the compounds contain ionizable groups, they are usually tested for water solubility at different pH conditions.

       Liposolubility is another very important physicochemical parameter of compounds, which affects their solubility, absorption, membrane permeability, plasma protein binding, tissue distribution, entry into brain tissue, and clearance pathways. The liposolubility of compounds not only affects their recognition with targets, but also their interaction with CYP450, HERG binding, and PXR-mediated enzyme induction. The liposolubility of compounds is usually measured by Log D, and another commonly used parameter is Log P. Since most compounds are ionized at physiological pH (7.4), the liposolubility is often determined at pH 7.4, i.e. Log D7.4.