The equation that express the combined effect of the organic modifier content and mobile phase pH has been used to predict the chromatographic behavior of flurbiprofen, ibuprofen, diclofenic acid, ketoprofen, fenoprofen, naproxen, bezafibric acid and clofibric acid. Correlations between the retention factors of the solutes and pH of the mobile phase were determined from a set of 40 chromatograms for each compound at four different levels of acetonitrile composition (40, 45, 50 and 55 %, v/v), and at ten pH values in each acetonitrile-water mixtures. In this way, a complete description of the retention behavior of each solute in the space defined by the pH and organic modifier percentages variables was obtained. The optimized chromatographic condition was applied to quantitative determination of flurbiprofen, ibuprofen, and diclofenic acid in pharmaceutical dosage forms.

Imidazoles are well known heterocyclic compounds having important feature of a variety of medicinal agents. Studies with imidazole containing compounds are great importance in the clinical use of drugs. The presence of imidazole group in the molecules of lanoconazole (LCZ) and butoconazole (BCZ) is very important for its chemical and analytical behavior. Target analytes were efficiently separated with a Pinnacle DB Cyano column (5 µm, 4.6 x 250 mm I.D.) and oxiconazole (OCZ) used as an internal standard. In this study, correlation between the retention factors of the solutes and pH of the mobile phase was determined at ten pH values in acetonitrile-water binary mixture. In optimization condition, quantification of these drugs were performed in human urine. The linear responses were observed over a wide concentration range (6.25.