2026-04-17T20:33:43Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1619862025-12-04T19:36:52Zcom_2072_1057col_2072_478813col_2072_478917

00925njm 22002777a 4500 dc Fernández-Pumarega, Alejandro author Amézqueta, Susana author Fuguet i Jordà, Elisabet author Rosés Pascual, Martí author 2020-05-22T09:02:53Z 2020-05-22T09:02:53Z 2018-03-25 2020-05-22T09:02:53Z Previous studies have shown that a microemulsion electrokinetic chromatography (MEEKC) system can estimate the logarithm of the octanol-water partition coefficient (log Po/w) of neutral solutes. In the present work, the applicability of the method to partially and fully ionized acids has been evaluated. Naproxen, a monoprotic acid, has been used as test solute. The retention factor (k) of this compound has been measured in MEEKC at several values of pH and the retention factor-pH profile has been established. As log Po/w correlates with log kMEEKC for neutral compounds, this correlation has been used to estimate the logarithm of the octanol-water partition coefficient of the neutral (log Po/w(HA)), and the fully ionized (log P o/w(A-)) forms of naproxen. Then, the logarithm of the octanol-water distribution coefficient (log Do/w) of the partially ionized form of the acid has been estimated. The comparison of the estimated values with the ones obtained experimentally using the classical procedures, such as the shake-flask method, shows differences under 0.4 log Do/w units either if the acid is partially ionized or in its neutral form in the most part of the pH range. However, the method overestimates the log Do/w of the highly (>99.5 %) or fully ionized form of naproxen Electroforesi capil·lar Lipofília Capillary electrophoresis Lipophilicity Feasibility of the estimation of octanol-water distribution coefficients of acidic drugs by microemulsion electrokinetic chromatography