Estimation of thermodynamic acidity constants of some penicillinase-resistant penicillins

Demiralay E. C. , ÜSTÜN Z., Daldal Y. D.

JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS, vol.91, pp.7-11, 2014 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 91
  • Publication Date: 2014
  • Doi Number: 10.1016/j.jpba.2013.12.008
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.7-11
  • Keywords: Thermodynamic acidity constants, Polarity parameter, Activity coefficients, Water-acetonitrile binary mixture, PHASE LIQUID-CHROMATOGRAPHY, WATER MOBILE PHASES, DISSOCIATION-CONSTANTS, IONIZABLE COMPOUNDS, HPLC METHOD, RETENTION, PH, ANTIBIOTICS, PARAMETER, SOLVENT
  • Süleyman Demirel University Affiliated: Yes


In this work, thermodynamic acidity constants ((s)(s)pK(a)) of methicillin, oxacillin, nafcillin, cloxacilin, dicloxacillin were determined with reverse phase liquid chromatographic method (RPLC) by taking into account the effect of the activity coefficients in hydro-organic water-acetonitrile binary mixtures. From these values, thermodynamic aqueous acidity constants of these drugs were calculated by different approaches. The linear relationships established between retention factors of the species and the polarity parameter of the mobile phase (E-T(N)) was proved to predict accurately retention in LC as a function of the acetonitrile content (38%, 40% and 42%, v/v). (C) 2013 Elsevier B.V. All rights reserved.