title: Simultaneous determination of bifonazole and tinctures of calendula flower in pharmaceutical creams by reversed-phase liquid chromatography.
abstract: The aim of this research was to develop and validate a sensitive, rapid, easy, and precise reversed-phase liquid chromatography (LC) method for stability studies of bifonazole (I) formulated with tinctures of calendula flower (II). The method was especially developed for the analysis and quantitative determination of I and II in pure and combined forms in cream pharmaceutical formulations without using gradient elution and at room temperature. The influence on the stability of compound I of temperature, artificial radiation, and drug II used for the new pharmaceutical design was evaluated. The LC separation was carried out using a Supelcosil LC-18 column (25 cm x 4.6 mm id, 5 microm particle size); the mobile phase was composed of methanol-0.1 M ammonium acetate buffer (85 + 15, v/v) pumped isocratically at a flow rate of 1 mL/min; and ultraviolet detection was at 254 nm. The analysis time was less than 10 min. Calibration graphs were found to be linear in the 0.125-0.375 mg/mL (rI = 0.9991) and 0.639-1.916 mg/mL (rII = 0.9995) ranges for I and II, respectively. The linearity, precision, recovery, and limits of detection and quantification were satisfactory for I and II. The results obtained suggested that the developed LC method is selective and specific for the analysis of I and II in pharmaceutical products, and that it can be applied to stability studies.
authors.affiliation: Universidad Nacional de Córdoba, Facultad de Ciencias Quimicas, Departamento de Farmacia, 5000 Córdoba, Argentina.
authors.forename: Carola F
authors.initials: CF
authors.lastname: Ferreyra
authors.forename: Cristina S
authors.initials: CS
authors.lastname: Ortiz
mesh_terms: D000085:Acetates / Q000737:chemistry; D000935:Antifungal Agents / Q000032:analysis; D002021:Buffers; D020838:Calendula / Q000378:metabolism*; D002138:Calibration; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002853:Chromatography, Liquid / Q000379:methods*; D004304:Dosage Forms; D006358:Hot Temperature; D007093:Imidazoles / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D000432:Methanol / Q000737:chemistry; D004364:Pharmaceutical Preparations / Q000032:analysis*; D010777:Photochemistry; D010936:Plant Extracts / Q000032:analysis*; D015203:Reproducibility of Results; D013053:Spectrophotometry; D013696:Temperature; D013997:Time Factors
chemical_list: D000085:Acetates; D000935:Antifungal Agents; D002021:Buffers; D004304:Dosage Forms; D007093:Imidazoles; D004364:Pharmaceutical Preparations; D010936:Plant Extracts; C036596:bifonazole; C018824:ammonium acetate; D000432:Methanol