Person: TIRIS, GİZEM
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TIRIS
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GİZEM
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- PublicationMetadata onlyA 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, GİZEM
- PublicationMetadata onlyDetermination of Bisoprolol Fumarate and Hydrochlorothiazide in Combined Tablet Dosage Form By Novel Spectrophotometric Techniques(2017-09-13) ERK, Nevin; TIRIS, GİZEM; TIRIS, GİZEM
- PublicationMetadata onlyAN UPLC METHOD FOR THE DETERMINATION OF SORAFENIB IN HUMAN PLASMA BY FLUORIMETRIC DETECTION WITH PRE-COLUMN DERIVATIZATION AND APPLICATION TO A PHARMACOKINETIC STUDY(2022-01-01T00:00:00Z) TIRIS, GİZEM; Tekkeli, S. Evrim Kepekci; Önal, Cem; Ceylan, Burhan; ÖNAL, Armağan; TIRIS, GİZEM© 2022, Publishing House of the Romanian Academy. All rights reserved.This research presents a new, sensitive and selective UPLC method with fluorometric detection for the determination of sorafenib in human plasma and application of the method to a pharmacokinetic study. Sorafenib was precolumn derivatized with 7-chloro-4-nitrobenzofurazan (NBD-Cl) and the separation of the fluorescent derivative was performed with a C18 column (50 mm x 2.1 mm, 1.7 µm) at 40ºC using a mobile phase composed of acetonitrile-0.1% trifluoroacetic acid in water (60:40, v/v) by isocratic elution with flow rate of 0.5 mL min−1. The injection volume was 7 µL. The method depends on the measurement of the derivative using fluorescence detection (λex = 398 nm, λem = 425 nm). The retention time of sorafenib was 3.10 ± 0.02 min. The novel method was validated in accordance with ICH criteria by studying on the parameters such as specificity, linearity, precision, accuracy and robustness. The method was determined to be linear in a concentration range of 0.25-10 µg mL−1 with the correlation coefficient of 0.9995. Limit of detection and quantitation were found to be 0.075 and 0.25 µg mL−1, respectively. Intraday and interday RSD values were less than 5.48%. The plasma concentration–time profile and pharmacokinetic parameters such as AUC0–t, AUC0–∞, Cmax, tmax, t1/2 were measured according to the assays. The proposed method is feasible to investigate the bioequivalence and bioavailability and routine analysis of the drug in plasma.
- PublicationMetadata onlyLow-cost voltammetric sensor based on reduced graphene oxide anchored on platinum nanoparticles for robust determination of Favipiravir in real samples(2023-01-01) Bouali W.; ERK N.; Kholafazadehastamal G.; Naser M.; TIRIS G.; TIRIS, GİZEM© 2022 Elsevier B.V.This research describes a simple, sensitive, and disposable modified glassy carbon electrode constructed using platinum nanoparticles anchored on reduced graphene oxide nanocomposite as a conductive modifier (Pt@rGO/GCE) to detect an anti-coronavirus drug, Favipiravir (FAV). The as-synthesized nanocomposite was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), and atomic force microscopy (AFM). Under optimized conditions, the square wave voltammetry (SWV) method was used to determine trace amounts of FAV in real samples. The proposed electrode demonstrated a wide linear concentration range of 3.16 to 100.0 μM with a low detection limit (LOD) of 2.46 μM. Moreover, the developed electrode showed outstanding selectivity in the presence of several interferences with high repeatability and reproducibility. Finally, the developed electrode was applied to detect FAV in human plasma and pharmaceutical samples.
- PublicationMetadata onlyOptimization of a new controlled release oral dexketoprofen formulation(2018-05-08) Sevim, Bilgesu Beria; Çerçi, Buse Hande; Küçük, Zeynep; BAHADORİ, FATEMEH; Kazdal, Fatma; Eskandari, Zahra; Tırıs, GİZEM; DEMIRAY, MUTLU; BAHADORİ, FATEMEH; TIRIS, GİZEM
- PublicationMetadata onlyDetermination 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.
- PublicationMetadata onlySmart Spectrophotometric Determination of Tenofovir Disoproxil and Emtricitabine in Medical Dosage Formulations By Using Unified Regression Equation(2019-12-23T00:00:00Z) Lotfy, Hayam M.; Erk, Nevin; Tırıs, Gizem; TIRIS, GİZEM
- PublicationMetadata onlyELECTROCHEMICAL DETERMINATION OF ANTINEOPLASTIC DRUG IN HUMAN PLASMA BY MODIFIED GLASSY CARBON ELECTRODE(2021-06-25T00:00:00Z) Mehmandoust, Mohammed; Erk, Nevin; Tırıs, Gizem; TIRIS, GİZEM
- PublicationMetadata onlyRATIO DERIVATIVE AND DIFFERENCE SPECTROPHOTOMETRIC TECHNIQUES FOR SIMULTANEOUS DETERMINATION OF CARVEDILOL AND HYDROCHLOROTHIAZIDE IN MARKETED TABLETS(2018-06-29) ERK, NEVİN; TIRIS, GİZEM; TIRIS, GİZEM
- PublicationMetadata onlyUltra fast liquid chromatographic analysis of nonsteroidal anti-inflammatory drugs with fluorimetric detection in tap water, urine, and pharmaceutical samples(2022-06-01T00:00:00Z) Onal, Cem; TIRIS, GİZEM; Tekkeli, Evrim Kepekci; Onal, Armagan; TIRIS, GİZEM; TEKKELİ, ŞERİFE EVRİMA novel analytical method based on ultra-fast liquid chromatography using fluorimetric detector was developed and validated for determination of non-steroidal anti-inflammatory drugs (NSAIDs) (ibuprofen (IBP), etodolac (ETD), dexketoprofen (DKP), sodium diclofenac (SDCF), and naproxen (NPX) in tap water, urine and pharmaceutical samples. Precolumn derivatisation of targeted NSAIDs was carried out with 4-bromomethyl-7-methoxy coumarin (BrMmC) using dibenzo-18-crown-6-ether as reaction catalyst leading to the formation of a fluorescent compound. The obtained fluorescent compound of NSAIDs were measured at excitation wavelength as 325 nm, and emission wavelength of 395 nm. Optimum analytical conditions were carefully studied and improved. C18 column, with the dimensions of 4.0 x 100 mm and 3 mu m particle size, was used. Gradient elution with methanol: water 40:60; v/v (eluent A) and acetonitrile 100% (eluent B) were used as mobile phase and flow rate of 0.4 mL/min. The linearity range of the analytes were between 0.01-10.0 mu g mL(-1). Recovery values obtained from pharmaceutical preparations were found as 100.04%, 99.99%, 100.09%, 99.98% and 100.47% for IBP, ETO, DKP, SDCF, NPX, respectively. LOD values were found to vary between 0.00009 mu g mL(-1) and 0.00048 mu g mL(-1) in tap water, urine and pharmaceutical samples. The optimised technique was successfully applied for the determination of NSAIDs in tap water, urine, and pharmaceutical specimen. The specified NSAIDs were not found in real tap water samples.