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Now showing 1 - 10 of 13
  • PublicationMetadata only
    Simultaneous determination of hydrochlorothiazide, amlodipine, and telmisartan with spectrophotometric and HPLC green chemistry applications.
    (2022-06-03T00:00:00Z) Tiris, GİZEM; Mehmandoust, Mohammad; Lotfy, Hayam M; Erk, Nevin; Joo, Sang-Woo; Dragoi, Elena-Niculina; Vasseghian, Yasser; TIRIS, GİZEM
  • PublicationMetadata only
    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.
  • PublicationMetadata only
    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, GİZEM
    Background: 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.
  • PublicationMetadata only
    High performance liquid chromatographic analysis of lercanidipine in human breast milk
    A 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.
  • PublicationMetadata only
    A review of the currently developed analytical methods for the determination of biogenic amines in food products
    (2023-01-01T00:00:00Z) TIRIS, GİZEM; Sare Yanıkoğlu, RABİA SARE; Ceylan, Burhan; EGELİ, DERYA; Kepekci Tekkeli, Evrim; ÖNAL, Armağan; TIRIS, GİZEM; YANIKOĞLU, RABİA SARE; EGELİ, DERYA
    © 2022Biogenic amines (BAs) are group of substances that are formed from amino acids by decarboxylation or amination and transamination of aldehydes and ketones. They may have either aliphatic, aromatic or heterocyclic structure. Their quantity determines their effects, optimum amounts are essential for physiological functions, but excess of BAs causes various toxic effects through out human body. BAs are presented in a wide variety of fermented foods such as fish, meat, milk products and some kinds of beverages like wine, beer and some fruit juices. In order to quantify their intake by food products are important, the methods that provide determination of BAs in food products are a matter of priority. Mostly, liquid chromatographic (LC) methods are preffered. Their amine groups are able to be derivatized by so many fluorogenic reagents. It is possible to combine LC systems with UV–vis. absorption spectrometric, fluorimetric and mass spectrometric detectors. Due to the fact that BAs are important markers for food quality and important for health, in this article LC methods for the determination of BAs in foods were reviewed from 2012 to present.
  • PublicationMetadata only
    The power of High Impact Amplitude Manipulation (HIAM) technique for extracting the basic spectra of two Fixed-dose combinations (FDC) -Spectrophotometric purity analysis via spectral contrast angle
    (2022-05-15T00:00:00Z) Saleh, Sarah S.; Lotfy, Hayam M.; TIRIS, GİZEM; ERK, NEVİN; El-Naem, Omnia A.; TIRIS, GİZEM
    © 2022 Elsevier B.V.HIAM technique allows the extraction of the original constant signal of each single component out of interference signals of a mixture and further transformed into basic spectrum (D0). It includes the methods: ratio subtraction coupled with unified constant subtraction (RS-UCS), constant center (CC) and constant extraction (CE). The technique was introduced for the analysis of two pharmaceutical formulations used to treat cardiovascular diseases. The formulations are binary combinations of Amlodipine (AML) with either Atorvastatin (ATR) or Candesartan (CND) which shows interefernce absorbance signals. The technique was valid over the linearity range of (5.0–35.0 µg/ml) for AML, ATR and CND with recovery percentage 100.40 ± 1.88, 100.00 ± 0.86 and 99.83 ± 1.07, respectively. The extracted signals were tested for its purity by spectral contrast angle (cos θ) to illustrate the efficency of the HIAM technique where cos θ values ranges from (0.9902 to 0.9986). The presented technique was fully validated regarding ICH guidelines and were statistically compared using one-way ANOVA at 95% confidence.
  • PublicationMetadata only
    Determination of dihydrocapsaicin adulteration in dietary supplements using LC-MS/MS
    (2020-01-01T00:00:00Z) DİNCEL, DEMET; Olgan, Hatice; Canbaloglu, Zeynep; Yalcin, Sule; Erkucuk, Aysen; TIRIS, GİZEM; GÖREN, AHMET CEYHAN; DİNCEL, DEMET; TIRIS, GİZEM; GÖREN, AHMET CEYHAN
    Adulterations of dietary supplements are serious threats to public health in all around of world. Nowadays, in order to obtain the intended effect from natural remedies, the adulteration of natural products via artificial or harmful chemicals are increasing. A rapid LC-MS/MS method for determination of capsaicin and dihydrocapsaicin in dietary supplements via Fortis C18 (150 x 3 mm; 3 mu m) column at 25 degrees C was developed and validated in a mixture of mobile phase A (1 % formic acid solution and 0.1 % ammonium formate in water) and B (1 % formic acid solution and 0.1 % ammonium formate in methanol) with gradient program at a flow rate of 0.35 mL/min. The recoveries of developed methods weytre obtained in the range of % 95.4-106.3 for capsaicin and % 96.3-108.9 for dihydrocapsaicin. This study shows that synthetic compound dihydrocapsaicin is widely use in dietary supplements products for adulteration to increase the effects of product without any declaration.
  • PublicationMetadata only
    Ultra 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 EVRİM
    A 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.
  • PublicationMetadata only
    (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 only
    Trade-off efficacy and data processing strategy in the power of spectral resolution of co-formulated antihypertensive pharmaceuticals
    (2021-02-01T00:00:00Z) Rostom, Yasmin; Lotfy, Hayam M.; Ozturk, Meltem; Tiris, Gizem; ERK, NEVİN; Saleh, Sarah S.; TIRIS, GİZEM
    Versatile, extraction-free univariate spectrophotometric methods have been modified to get effective spectral resolution of mixtures in accordance with their feature challenges. The proposed methods have been applied and validated for analyzing some antihypertensive medicines in their co-formulated medicinal products. Two mixtures have been used: the first one [Mix I (OLM/ADB)] is composed of Olmesartan medoxomil (OLM) and Amlodipine besylate (ADB) with partly-overlapped spectra while the second [Mix II (TEL/HCT)] is made up Telmisartan (TEL) and Hydrochlorothiazide (HCT) with total-overlapped spectra. Induced dual wavelength, absorbance correction and ratio subtraction coupled with constant multiplication methods were applied to Mix I (OLM/ADB), while dual wavelength, advanced absorbance subtraction and constant center coupled with spectrum subtraction methods were applied to Mix II (TEL/HCT). Calibration graphs were established with good correlation coefficients. The methods exhibit significant advantages as simplicity, sensitivity, minimal data manipulation besides optimum robustness. Selectivity was inspected using lab-mixtures with diverse ratios. Accuracy, precision and repeatability were found to be within the acceptable limits. The proposed methods are good enough to be used for co-assay of analytes in combined forms without any interfering from excipients. Moreover, all results were estimated in accordance with ICH criteria and successfully compared with those of the reported methods applying t-test and F-test at 95% confidence level. Generally, these methods can be used efficiently for routine quality control testing. (C) 2020 Elsevier B.V. All rights reserved.