Lipophilicity of amphoteric and zwitterionic compounds: a comparative study of determination methods

Common drugs intended for action in plasma (antibacterials, antiallergics, diuretics¿) often display both acidic and basic behavior, and some of these amphoteric compounds can appear as zwitterions. In such cases, accurate profiling of lipophilicity vs. pH, which plays a fundamental role in drug pha...

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Detalles Bibliográficos
Autores: Ràfols Llach, Clara, Subirats i Vila, Xavier, Rubio, Javier, Rosés Pascual, Martí, Bosch, Elisabeth
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2016
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/102798
Acceso en línea:https://hdl.handle.net/2445/102798
Access Level:acceso abierto
Palabra clave:Lipofília
Cromatografia
Química farmacèutica
Lipophilicity
Chromatography
Pharmaceutical chemistry
Descripción
Sumario:Common drugs intended for action in plasma (antibacterials, antiallergics, diuretics¿) often display both acidic and basic behavior, and some of these amphoteric compounds can appear as zwitterions. In such cases, accurate profiling of lipophilicity vs. pH, which plays a fundamental role in drug pharmacokinetics, might be complex. In the present work two common lipophilicity estimation methods based on the drug distribution between 1-octanol and aqueous buffer i.e. phase equilibration (shake-flask) and two-phase titration (potentiometry), were compared with a high-throughput lipophilicity index, the Chromatographic Hydrophobicity Index (CHI). The results were also compared with log Do/w pH-profiles calculated by different algorithms from ACD/Labs. Accurate and similar results were obtained for both octanol-water approaches but, due to the lower determination times and the absence of different ion-pairing buffers, potentiometry was shown to be the most convenient method. CHI vs. pH profiles provide rapid and efficient information, which is very convenient for lipophilicity screening purposes, but may differ slightly from shake-flask and potentiometric results.