title: Development and validation of spectrophotometric and high-performance column liquid chromatographic methods for the simultaneous determination of dienogest and estradiol valerate in pharmaceutical preparations.
abstract: Simultaneous determination of dienogest (DIE) and estradiol valerate (EST) in sugar-coated tablets was performed by using HPLC and spectrophotometry. In HPLC, the separation was achieved on an ACE C8 column using the mobile phase acetonitrile-NH4NO3 (0.03 M, pH 5.4; 70 + 30, v/v) at a flow rate of 2 mL/min. The detection wavelength was 280 nm, and cyproterone acetate was selected as an internal standard. The linearity range was 3.0-45.0 microg/mL for DIE and 18.0-100.0 microg/mL for EST. As spectrophotometric methods, two chemometric methods, principal component regression and partial least-squares, were developed. In the chemometric techniques, the concentration data matrix was prepared by using mixtures containing these drugs in methanol-water (3 + 1, v/v). The absorbance data matrix corresponding to the concentration data matrix in these methods was obtained by the measurement of absorbances in their zero-order spectra; then, the calibration was obtained by using the data matrix for the prediction of unknown concentrations of DIE and EST in their binary mixture. Working ranges were found as 2.0-24.0 microg/mL for DIE and 20.0-270.0 microg/mL EST in the methods. These three developed methods were validated and successfully applied to a pharmaceutical preparation, a sugar-coated tablet, and the results were compared with each other.
authors.affiliation: University of Ankara, Faculty of Pharmacy, Department of Analytical Chemistry, Tandogan, Ankara, Turkey.
authors.forename: Mehmet Gökhan
authors.initials: MG
authors.lastname: Cağlayan
authors.forename: Ismail Murat
authors.initials: IM
authors.lastname: Palabiyik
authors.forename: Feyyaz
authors.initials: F
authors.lastname: Onur
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004958:Estradiol / Q000031:analogs & derivatives* / Q000032:analysis; D016018:Least-Squares Analysis; D009277:Nandrolone / Q000031:analogs & derivatives* / Q000032:analysis; D004364:Pharmaceutical Preparations / Q000032:analysis; D025341:Principal Component Analysis; D013053:Spectrophotometry / Q000379:methods*
chemical_list: D004364:Pharmaceutical Preparations; C023635:dienogest; D004958:Estradiol; D009277:Nandrolone