DEVELOPMENT OF A CHROMATOGRAPHIC METHOD FOR THE SIMULTANEOUS DETERMINATION OF SILDENAFIL AND DAPOXETINE
Project no. 20789 · Status: Kapanmış (Yayın bekleniyor) · 2019
Summary
Dapoxetine and Sildenafil active ingredients are used in the treatment of early ejaculation and erectile dysfunction problems, respectively. Pharmaceutical preparations where these two active substances are used together have started to be registered in the world. Therefore, simultaneous determination of these two molecules in both pharmaceutical dosages and plasma has become important. The aim of the thesis is to develop a method that can be used in bioequivalence studies with liquid-liquid extraction technique for these active substances. Dapoxetine and Sildenafil were determined simultaneously with the Liquid Chromatography Mass Spectrometer (LC-MS/MS) system using the liquid-liquid extraction technique in the sample preparation stage. 305.8 m/z for Dapoxetine, 474.8 m/z for Sildenafil and 389.7 m/z for Tadalafil which is used as internal standard, were determined as the main ion. For the fragmentation ions, 100.1, 157 and 268 m/z were observed respectively. The instrument working conditions are optimized by taking into account parameters; such as separation power, selectivity and retention times. In the liquid-liquid extraction technique, EMA validation parameters such as accuracy, linearity, repeatability, selectivity, matrix effect, stability, dilution integrity were examined for the method validation. In addition, lower limit of quantitation of liquid-liquid extraction method are 0.04 ng/mL, 2.00 ng / mL for Dapoxetine and Sildenafil respectively. The linear calibration curve ranges varied between 0.04 - 1.00 and 2.00 - 40.0 ng/mL for dapoxetine and Sildenafil, respectively. Recovery values are in the range of 87.5 - 112.5% for Dapoxetine and 85 - 113.5% for Sildenafil at low, medium and high concentrations. Keywords: Dapoxetine, Sildenafil, Tadalafil, liquid-liquid extraction, LC-MS/MS