Person: TIRIS, GİZEM
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Publication Determination of active ingredients in antihypertensive drugs using a novel green HPLC method approach(2022-09-01T00:00:00Z) TIRIS, GİZEM; Mehmandoust, Amirhossein; Karimi, Fatemeh; ERK, NEVİN; TIRIS, GİZEM© 2022 Elsevier LtdA novel, sensitive, fast, and pratic RP-HPLC methods were presented for the quantitative amounts of Telmisartan (TEL) and Olmesartan (OLM) in the presence of Amlodipin (AML) in a binary mixture of pharmaceutical preparation. Waters Spherisorb ODS-2 C18 column was used for separation. These methods were valid over linearity ranges of 2.5–30 μμg/mlL, 2–85 μμg/mlL, and 2–35 μμg/mlL for OLM, TEL, and AML, respectively. The mobile phase system consisted of acetonitrile:methanol: phosphate buffer at pH 3.0 (65:5:30 v/v/v), and the flow rate was 1,5 mlL/min for OLM and AML. The mobile system-s other mixture (TEL and AML) was acetonitrile:methanol: phosphate buffer at pH 2.5 (65:5:30 v/v/v), and the flow rate was 1,5 mlL/min. These procedures were successfully applied to bulk, laboratory synthetic mixture, and medicinal dosage forms to use active ingredients quantitatively. The studied methods were validated according to ICH guidelines. In the developed HPLC method, the limit of detection values was found to be 0.020 μμg/mlL for TEL, 0.025 μμg/mlL for OML, and 0.070 μμg/mlL for AML. The correlation coefficients for the HPLC method were found to be 0.9938 for TEL, 0.9996 for OML, and 0.9982 for AML. The calibration range is between 2.5 and -30, 5–35, and 2–85 μμg/mlL for OLM, AML, and TEL, respectively. The proposed HPLC method is a convenient, effective, sensitive, green, and time-saving method for the rapid determination of TEL and OLM in the presence of AML.Publication High performance liquid chromatographic analysis of lercanidipine in human breast milk(2019-01-01) Tekkeli, Evrim Kepekci; GAZİOĞLU, IŞIL; TIRIS, GİZEM; Onal, Cem; TEKKELİ, ŞERİFE EVRİM; GAZİOĞLU, IŞIL; TIRIS, GİZEMA simple, rapid, precise and accurate isocratic reversed phase HPLC method was developed and validated for the determination of lercanidipine hydrochloride in pharmaceutical tablets and spiked human breast milk. The chromatographic separation was achieved on C18 (250x4.6 mmx5 mu m) column using a mobile phase consisting of acetonitrile and phospate buffer (pH=4) (55:45, v/v) at a flow rate of 1.1 mL/min and UV detection at 237 nm. The linearity of the proposed method was investigated in the range of 1.0-40 mu g/mL (r(2)=0.9990). The method was validated in terms of accuracy, precision, reproducibility, specificity, robustness, and detection and quantification limits, in accordance with ICH guidelines. The proposed method is found as suitable for routine quantification of lercanidipine in human breast milk.Publication A new HPLC method for the determination of Allicin and S-Allyl cysteine in garlic (Allium sativum L.) extracts(2020-09-01T00:00:00Z) BUCAK, Seden; TEKKELİ, ŞERİFE EVRİM; CEYLAN, BURHAN; TIRIS, GİZEM; TEKKELİ, ŞERİFE EVRİM; TIRIS, GİZEMPublication Development and Application of Advanced Absorbance Subtraction Spectrophotometric Method for the Quantification of the Antiretroviral Compounds in Medical Dosage forms(2019-12-03T00:00:00Z) Lotfy, Hayam M; TIRIS, GİZEM; ERK, NEVİN; TIRIS, GİZEMPublication A novel stability-indicating method for determination of a new antidepressant effect of vortioxetine in a pharmaceutical formulation by using RP-HPLC(2020-12-01T00:00:00Z) TIRIS, GİZEM; Alver, Cansu; ERK, NEVİN; TIRIS, GİZEMBackground: A novel rapid, accurate, and stability-indicating reversed-phase high performance liquid chromatographic (RP-HPLC) and first derivative spectrophotometric determination were explained for the assay of vortioxetine (VRT) in bulk and pharmaceutical formulations. For RP-HPLC method, optimal separation and determination of VRT were achieved with a Waters Symmetry C-18, (100 x 4.6 mm, 3.5 mu m) analytical column using a mobile phase consisting of methanol:0.05 M potassium dihydrogen phosphate (pH:3.0 +/- 0.05) (30:70, v/v) in isocratic mode with flow rate of 1.3 mL min(-1). Injection volume was 20 mu L. The maximum absorption wavelength of VRT is 225.0 nm; hence, 225.0 nm was studied as the detection wavelength and column at 50 degrees C temperature. The caffeine was used as the internal standard (IS). On the other hand, the first derivative spectrophotometric method for the analysis of vortioxetine was performed by measuring the amplitude at 251.7 and 272.6 nm.Publication Quantitative Analysis Of Amlodipine And Atorvastatin By Using Constant Center Spectrophotometric Technique(2018-06-29) Lotfy, Hayam; ERK, Nevin; TIRIS, GİZEM; ŞAHİN, EGEMEN; TIRIS, GİZEMPublication Sensitive and Rapid Determination of Protease Inhibitors in Pure Drugs and Their Mixtures using High Performance LiquidChromatography(2017-10-07T00:00:00Z) TIRIS, GİZEM; ERK, NEVİN; TIRIS, GİZEMPublication A sensitive voltammetric sensor for specific recognition of vitamin C in human plasma based on MAPbl(3) perovskite nanorods(2022-01-01T00:00:00Z) TIRIS, GİZEM; Khoshnavaz, Yasamin; Oven, Elif Naz; Mehmandoust, Mohammad; ERK, NEVİN; TIRIS, GİZEMA novel and sensitive electrode was suggested for the rapid determination of ascorbic acid (AA) using a glassy carbon electrode (GCE) modified with synthesized MAPbl(3) and L-cys (L-cys/MAPbl(3)/GCE). Determination of ascorbic acid as an important component of the human diet due to help in decreasing blood pressure and improving endothelial function is crucial. The synthesized MAPbl(3) was characterized by different methods, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). The fabricated electrode exhibited superior electrical conductivity and fast electron transfer kinetics. The results illustrated that the developed electrode had an outstanding electrocatalytic activity towards the oxidation of AA in 0.1 M Britton-Robinson buffer(B-R) as a supporting electrolyte. The modified electrode demonstrated a linear range in differential pulse voltammetry of 0.02-11.4 mu M with a low detection limit of 8.0 nM for ascorbic acid. It can be stated that the proposed sensor can be successfully applied to the determination of ascorbic acid in human plasma samples.Publication RAPID DETERMINATION OF ANTIHYPERTENSIVE AGENTS USING RATIO DIFFERENCE AND RATIO DERIVATIVE SPECTROPHOTOMETRIC TECHNIQUE(2018-09-10) TIRIS, GİZEM; ERK, Nevin; TIRIS, GİZEMPublication Determination of Bisoprolol Fumarate and Hydrochlorothiazide in Combined Tablet Dosage Form By Novel Spectrophotometric Techniques(2017-09-13) ERK, Nevin; TIRIS, GİZEM; TIRIS, GİZEM