Chromatographic Determination of Aqueous Dissociation Constants of Some Water-Insoluble Nonsteroidal Antiinflammatory Drugs

The adsorption of Naproxen enantiomers on the chiral stationary phase Whelk-O1 under reversed-phase conditions: The effect of buffer composition

“…However, as we use in the calculation the effective autoprotolysis constant of the medium, we may approximate the virtual complex scheme of the autoprotolysis of the methanol-water mixture with a single component equilibrium (10) [34], assuming S = OH . The values of the equilibrium constants pK N , pK A , and pK S in a 80:20 (v/v) methanol-water at ambient temperature are 6.58 [35], 6.49 [34], and 14.63 [34], respectively. Eqs.…”

Physicochemical Profiling in Drug Research and Development

“…In the recent years, capillary electrophoresis (CE) has proved to be a very powerful pK a determination method, being more sensitive and less sample consuming [11,16]. Some other methods such as NMR/pH titration [55], CD/pH titration [56], and chromatographic technique [57] have also been applied for special cases, but so far have not become routine techniques.…”

pKaDetermination

“…Oumada et al [46] described a new chromatographic method for determining the aqueous p K a values of drug compounds which are sparingly soluble in water. The method uses a rigorous intersolvent pH scale in a mobile phase consisting of a mixture of aqueous buffer and methanol.…”