Yazar "Kurnaz Yetim, Nurdan" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Yayın
    Magnetic micro solid-phase extraction for a novel UHPLC-DAD method for the determination of atomoxetine (ATX) in breast milk and human plasma
    (Academia Română, 2024) Ceylan, Burhan; Kurnaz Yetim, Nurdan; Özcan, Cemile; Koç, Mümin Mehmet; Önal, Cem
    Atomoxetine is a special pharmaceutics used for attention deficit hyperactivity disorder. It finds application in various age groups, including children, adolescents, and adults. Ultra high-performance liquid chromatographic technique (UHPLC) is an exceptional technique and provides swift, uncomplicated, and highly sensitive results. Such a technique has been formulated to analyse atomoxetine levels in both breast milk and human plasma. Magnetic micro solid phase extraction is simple, rapid, efficient, and precise method which was applied prior to chromatographic separation. In this method, magnetic adsorbents in the form of Fe3O4 magnetic nanoparticles were employed, and the adsorption process underwent optimization. Chromatographic separation was carried out using a reversed-phase C18 analytical column (5 μm × 4.6 mm × 150 mm) with a mobile phase composed of monobasic potassium dihydrogen orthophosphate (pH=6.8) and acetonitrile (50:50 v/v). The flow rate was set at 0.8 mL/min, and investigation was performed using DAD at 215±2 nm. The method's linearity was evaluated within the range of 0.5–20 μg/mL, achieving a correlation coefficient (r) of 0.999. Validation of the method encompassed accuracy, reproducibility, precision, robustness, specificity, quantification limits, and detection limits, adhering to EMA guidelines. The limit of detection (LOD) was found to be 0.03, while the limit of quantification (LOQ) was 0.11 μg/mL for both matrices. Interday and intraday relative standard deviation (RSD) values were determined to be below 2.5% for both assays. The suggested method is deemed to be a useful candidate for the conventional quantification of atomoxetine in human spiked breast milk and plasma.
  • Kapalı Erişim
    Yayın
    Nio nanoflower based sorbent extraction for a novel HPLC–UV method for the determination of solifenacin in human plasma and its application to a prototype pharmacokinetic study
    (Springer Nature Link, 2025) Ceylan, Burhan; Önal, Cem; Kurnaz Yetim, Nurdan; Hasanoğlu Özkan, Elvan; Önal, Armağan
    Solifenacin is an active pharmaceutical product used in overactive therapy. The main goal of this work was to develop a high-performance liquid chromatographic (HPLC) method with ultraviolet detection for measuring the amount of quanti fied solifenacin in human plasma samples that is rapid, straightforward, and accurate. Prior to chromatographic analysis, a nanomaterial-based sorbent extraction technique utilizing NiO nanoflowers was employed for plasma sample preparation. In this method, NiO nanoflowers were employed, and the adsorption process underwent optimization. Chromatographic separation was carried out using a reversed-phase C18 analytical column (5 µm×4.6 mm×150 mm) with a mobile phase composed of water (0.2% triethylamine) and acetonitrile (30:70 v/v), and the pH was adjusted to 3.5 with ortho-phosphoric acid. The flow rate was set at 1.0 mL/min, and the investigation was performed using UV at 220 nm. The retention time of solifenacin is 3.10±0.01 min. The linear behaviour of the proposed approach was examined in the 0.01–30 ng/mL range (r 2=0.9995). The proposed method is in alignment with the criteria established by the European Medical Agency (EMA) about the accuracy, precision, repeatability, specificity, robustness and detection and quantification. Limit of detection and limit of quantification are determined to be 0.003 and 0.01 ng/mL, whereas relative standard deviation was determined to be less than 2.75% for intra-run and inter-run measurements. The plasma concentration–time profile and pharmacokinetic parameters such as AUC0–t , AUC0–∞, Cmax, tmax, and t1/2, were calculated according to the assays. The proposed method is feasible to investigate the bioequivalence, bioavailability, and routine analysis of the drug in plasma.