scholarly journals A study of photodegradation of quetiapine by the use of LC-MS/MS method

2012 ◽  
Vol 10 (1) ◽  
pp. 232-240 ◽  
Author(s):  
Robert Skibiński
Keyword(s):  
Degradation Products ◽  
High Accuracy ◽  
Reversed Phase ◽  
Structural Elucidation ◽  
Methanol Solution ◽  
First Order ◽  
Photodegradation Product ◽  
First Order Kinetics ◽  
Photodegradation Products

AbstractPhotodegradation of quetiapine under UVC irradiation in methanol solution was investigated and structural elucidation of its photodegradation products was performed with the use of the reversed phase UHPLC system coupled with accurate mass hybrid ESI-Q-TOF mass spectrometer. During one run all essential data for the determination of photodegradation kinetics and for the structural elucidation of the products was collected with the use of auto MS/MS mode. Five degradation products were found and their masses and formulas were obtained with high accuracy (0.26–5.02 ppm). For all the analyzed compounds, MS/MS fragmentation spectra were also obtained allowing structural elucidation of the unknown degradation products and indicating photodegradation pathways of quetiapine. The main photodegradation product was identified as 2-[2-[4-(5-oxidodibenzo[b,f][1,4]thiazepin-11-yl)-1-piperazinyl]ethoxy]-ethanol and the photodegradation reaction yields the first-order kinetics with the rate constant k = 0.1094 h−1.

scholarly journals ESTUDO DE ESTABILIDADE DO FOSFATO DISSÓDICO DE PREDNISOLONA EM CONDIÇÕES DE ESTRESSE OXIDATIVO E TÉRMICO, EM FORMULAÇÃO ORAL

2018 ◽  
Vol 35 (4) ◽  
pp. 09
Author(s):  
Cleber Antonio Lindino ◽  
Marcia Lina Mitsui ◽  
Rodolfo Ortiguara ◽  
Daiane Felin ◽  
Mauricio Ferreira Da Rosa ◽  
...  
Keyword(s):  
High Performance ◽  
Dosage Form ◽  
Degradation Products ◽  
Degradation Process ◽  
Oral Solution ◽  
Form Solution ◽  
Oral Dosage ◽  
First Order ◽  
First Order Kinetics

This work was to investigate the process of degradation of the drug Prednisolone Sodium Phosphate (FSP) in oral solution dosage form through the degradation experiments, evaluating the parameters in accordance with Resolution 899/2003 ANVISA and the degradation process of the drug. The method by high performance liquid chromatography (HPLC) developed for the determination of the drug was validated to demonstrate its applicability as an indicator of stability, ensuring reliability. After the method be validated to study the degradation of the drug, it was shown that drastic conditions of oxidative stress (H O 30%) and 2 2 temperature 60°C, the degradation of the drug is dependent on its concentration (first order kinetics). The results were  satisfactory, showing that this method is suitable to investigate the formation of degradation products in oral dosage form solution

scholarly journals Determination of Chemical Stability of Two Oral Antidiabetics, Metformin and Repaglinide in the Solid State and Solutions Using LC-UV, LC-MS, and FT-IR Methods

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4430
Author(s):  
Anna Gumieniczek ◽  
Anna Berecka-Rycerz ◽  
Tomasz Mroczek ◽  
Krzysztof Wojtanowski
Keyword(s):  
High Temperature ◽  
Degradation Products ◽  
Degradation Kinetics ◽  
Magnesium Stearate ◽  
Oral Antidiabetics ◽  
First Order ◽  
First Order Kinetics ◽  
Ft Ir ◽  
The Stability

Firstly, metformin and repaglinide were degraded under high temperature/humidity, UV/VIS light, in different pH and oxidative conditions. Secondly, a new validated LC-UV method was examined, as to whether it validly determined these drugs in the presence of their degradation products and whether it is suitable for estimating degradation kinetics. Finally, the respective LC-MS method was used to identify the degradation products. In addition, using FT-IR method, the stability of metformin and repaglinide was scrutinized in the presence of polyvinylpyrrolidone (PVP), mannitol, magnesium stearate, and lactose. Significant degradation of metformin, following the first order kinetics, was observed in alkaline medium. In the case of repaglinide, the most significant and quickest degradation, following the first order kinetics, was observed in acidic and oxidative media (0.1 M HCl and 3% H2O2). Two new degradation products of metformin and nine new degradation products of repaglinide were detected and identified when the stressed samples were examined by our LC-MS method. What is more, the presence of PVP, mannitol, and magnesium stearate proved to affect the stability of metformin, while repaglinide stability was affected in the presence of PVP and magnesium stearate.

Development and Validation of a Stability-Indicating Chromatographic Method for the Determination of Indacaterol Maleate with Glycopyrronium Bromide in Mixture

2019 ◽  
Vol 15 (7) ◽  
pp. 694-702
Author(s):  
Sonia Talaat Hassib ◽  
Hanaa Abdelmenem Hashem ◽  
Marwa Ahmed Fouad ◽  
Nehal Essam Eldin Mohamed
Keyword(s):  
Chromatographic Method ◽  
Degradation Products ◽  
Reversed Phase ◽  
Chronic Obstructive ◽  
Forced Degradation ◽  
Uv Detector ◽  
Obstructive Pulmonary Disease ◽  
Mortality And Morbidity ◽  
Glycopyrronium Bromide

Introduction: (COPD) Chronic Obstructive Pulmonary Disease is a partially reversible and treatable lung disease, characterized by progressive limitation of airflow. It is one of the main causes of mortality and morbidity worldwide. Methods: An easy, precise and selective reversed-phase liquid chromatographic method, with stabilityindicating assay was established and validated for the determination of indacaterol maleate and glycopyrronium bromide in the mixture. In addition, a forced degradation study was performed for indacaterol maleate, comprised of hydrolysis by acid and base, degradation by oxidation and heat, and photo-degradation. Separation and forced degradation were done by isocratic elution using a reversed phase phenyl column and (methanol: phosphate buffer) at ratio (65:35, v/v) with 3.5 pH buffer as an eluent at 1 mL min-1 as a flow rate. Quantitation was accomplished using a UV detector at 210 nm. Results: The method showed good separation of glycopyrronium bromide, indacaterol maleate and its degradation products. Accuracy, linearity, and precision were acceptable over 10-160 µg mL-1 and 10- 80 µg mL-1 concentration range for indacaterol maleate and glycopyrronium bromide, respectively. Conclusion: The proposed method does not require any previously done separation steps, making it applicable for the analysis of the drugs under investigation in their pharmaceutically marketed preparations.

Development and validation of a fast and simple HPLC method for the simultaneous determination of aniline and its degradation products in wastewater

2016 ◽  
Vol 8 (30) ◽  
pp. 5949-5956 ◽  
Author(s):  
Soumia Boulahlib ◽  
Ali Boudina ◽  
Kahina Si-Ahmed ◽  
Yassine Bessekhouad ◽  
Mohamed Trari
Keyword(s):  
High Performance ◽  
Degradation Products ◽  
Reversed Phase ◽  
Hplc Method ◽  
Array Detector ◽  
Simple Method ◽  
Photodiode Array Detector ◽  
Photodiode Array ◽  
Development And Validation

In this study, a rapid and simple method based on reversed-phase high performance liquid chromatography (RP-HPLC) using a photodiode array detector (PDA) for the simultaneous analysis of five pollutants including aniline and its degradation products, para-aminophenol, meta-aminophenol, ortho-aminophenol and phenol, was developed.

New insights on the UV/TiO2 photocatalytic treatment of thiomersal and its 2-sulfobenzoic acid product

2021 ◽  
Vol 02 ◽  
Author(s):  
Emmanuel M. de la Fournière ◽  
Jorge M. Meichtry ◽  
Graciela S. Custo ◽  
Eduardo A. Gautier ◽  
Marta I. Litter
Keyword(s):  
Degradation Products ◽  
Acidic Ph ◽  
Cosmetic Products ◽  
Acid Product ◽  
First Order ◽  
First Order Kinetics ◽  
Photocatalytic Destruction ◽  
Pseudo First Order ◽  
Mineralization Degree ◽  
Suitable Technique

Background: Thiomersal (TM), a complex between 2-mercaptobenzoic acid (2-MBA) and ethylmercury (C2H5Hg+), is an antimicrobial preservative used in immunological, ophthalmic, cosmetic products, and vaccines. Objective: TM has been treated by UV/TiO2 photocatalysis in the presence or absence of oxygen at acidic pH. C2H5Hg+, 2-MBA, and 2-sulfobenzoic acid (2-SBA) were found as products. A 2-SBA photocatalytic treatment was undertaken to study sulfur evolution. Methods: Photocatalytic runs were performed using a UVA lamp (λmax = 352 nm), open to the air or under N2. A suspension of the corresponding TM or 2-SBA salt and TiO2 was prepared, and pH was adjusted. Suspensions were stirred in the dark for 30 min and then irradiated. TM, 2-MBA, 2-SBA, and C2H5Hg+ were quantified by HPLC, sulfur by TXRF, and the deposits on the photocatalyst were analyzed by chemical reactions. The mineralization degree was followed by TOC. Sulfate was determined using BaCl2 at 580 nm. Results: Photocatalytic destruction of TM and total C2H5Hg+ was complete under N2 and air, but TM degradation was much faster in air. The evolution of TM and the products followed a pseudo-first-order kinetics. Conclusion: TiO2-photocatalytic degradation is a suitable technique for the treatment of TM and its degradation products. In contrast to other organomercurial compounds, TM degradation is faster in the presence of O2, indicating that the oxidative mechanism is the preferred pathway. A significant TM mineralization (> 60%, NPOC and total S) was obtained. TM was more easily degraded than 2-SBA. Sulfate was the final product.

scholarly journals Photostability study of amlodipine besylate tablets packed in primary packaging

2021 ◽  
Vol 10 (1) ◽  
pp. 20-28
Author(s):  
Ivana Savić-Gajić ◽  
Ivan Savić ◽  
Predrag Sibinović ◽  
Valentina Marinković
Keyword(s):  
Mobile Phase ◽  
Limit Of Detection ◽  
Degradation Products ◽  
Hplc Method ◽  
Coefficient Of Determination ◽  
Amlodipine Besylate ◽  
Limit Of Quantification ◽  
First Order Kinetics ◽  
The Given

In this study, the modified stability-indicating RP-HPLC method was validated for quantitative analysis of amlodipine besylate in the presence of its impurity D (3-ethyl 5-methyl 2-[(2-aminoethoxy)methyl]-4-(2-chlorophenyl)-6-methylpyridine-3,5-dicarboxylate). The method was applied for the determination of an analyte in the tablets and irradiated samples packed in the primary packaging (Alu/PVC/PVDC blister packaging). The efficient chromatographic separation was achieved using a ZORBAX Eclipse XDB-C18 column (4.6×250 mm, 5 mm) with isocratic elution of mobile phase which consisted of acetonitrile:methanol:triethylamine solution (15:35:50, v/v/v) (pH 3.0). The flow rate of the mobile phase was 1 mL min-1, while the detection of amlodipine besylate was carried out at 273 nm. Amlodipine besylate and its impurity D were identified at the retention times of 16.529 min and 2.575 min, respectively. The linearity of the method with the coefficient of determination of 0.999 was confirmed in the concentration range of 10 - 75 µg mL-1 for amlodipine besylate. The limit of detection was 0.2 µg mL-1, while the limit of quantification was 0.66 µg mL-1. After UV and Vis radiation of the tablets packed in the primary packaging, the content of amlodipine besylate was reduced by 22.38% and 19.89%, respectively. The presence of new degradation products was not detected under the given chromatographic conditions. The photodegradation of amlodipine besylate followed pseudo-first-order kinetics. Based on the half-life of amlodipine besylate (38.4 days for UV radiation and 43.3 days for Vis radiation), it was concluded that amlodipine besylate in the tablets has satisfactory photostability after its packing in the Alu/PVC/PVDC blister packaging.

scholarly journals Fast and selective HPLC-DAD method for determination of pholcodine and related substances

2011 ◽  
Vol 30 (2) ◽  
pp. 139 ◽  
Author(s):  
Ana Petkovska ◽  
Hristina Babunovska ◽  
Marina Stefova
Keyword(s):  
Quality Control ◽  
Degradation Products ◽  
Ammonium Hydroxide ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Real Sample Analysis ◽  
Related Substances ◽  
Structural Analogues ◽  
Reliable Methods

Quality control of pharmaceuticals requires development of fast, efficient and reliable methods for determination of active compounds as well as known and very often unknown impurities within defined concentration ranges. In this work, a simple and rapid HPLC-UV-DAD method for identification and quantification of pholcodine process related impurities and some degradation products was developed and validated. Pholcodine and its five structural analogues such as morphine, codeine, thebaine, oripavine, and papaverine were separated in less than 10 minutes using reversed phase LiChrospher C-8 column. For optimal chromatographic performance with reproducible retention times, gradient elution with 2% ammonium hydroxide in water and acetonitrile was used. The method was validated by establishing its selectivity, specifity, sensitivity, linearity, intra- and inter-day precision and robustness. All tested parameters confirmed that the method is suitable for determination of pholcodine and its five impurities in pharmaceutical drug samples. The results obtained from real sample analysis give support to the suitability of the proposed method for the purpose of quality control.

Modified ferron assay for speciation characterization of hydrolyzed Al(III): a precise k value based judgment

2009 ◽  
Vol 59 (4) ◽  
pp. 823-832 ◽  
Author(s):  
Ye Changqing ◽  
Wang Dongsheng ◽  
Wu Xiaohong ◽  
Qu Jiuhui ◽  
John Gregory
Keyword(s):  
Kinetic Constant ◽  
Nonlinear Least Squares ◽  
Precise Determination ◽  
K Value ◽  
First Order ◽  
First Order Kinetics ◽  
Parallel Reactions

The speciation of Al-OH complexes in terms of Ala, Alb and Alc could be achieved by traditional ferron assay and Alb is generally considered as Al13, however, the inherent correlation between them remains an enigma. This paper presents a modified ferron assay to get precise determination of Al13 using nonlinear least squares analysis, and to clarify the correlation between Alb and Al13. Two parallel reactions conforming to pseudo-first-order kinetics can simulate the complicate reactions between polynuclear complexes and ferron successfully. Four types of experimental kinetic constant (k value) of Al-OH complexes can be observed by this method when investigating three typical aluminium solutions. Comparing with the results of 27Al NMR, the species with moderate kinetics around 0.001 s−1 can be confirmed to resemble to Al13 polycation. The other types of kinetics are also well-regulated in partially neutralized aluminium solutions with various OH/Al ratios (b values) in the range 0 ∼ 2.5. It would provide potential means to trace the in-situ formation of Al13 in dilute solutions such as coagulation with Al-based coagulants

scholarly journals Stress Degradation Studies and Kinetic Determinations of Duloxetine Enteric-Coated Pellets by HPLC

2010 ◽  
Vol 93 (6) ◽  
pp. 1829-1835 ◽  
Author(s):  
Patrícia Gomes ◽  
Nathalie R Wingert ◽  
Clésio S Paim ◽  
Elfrides E S Schapoval ◽  
Martin Steppe
Keyword(s):  
Degradation Products ◽  
Potassium Phosphate ◽  
Assay Method ◽  
Pharmaceutical Dosage Form ◽  
First Order Kinetics ◽  
Zero Order Kinetics ◽  
Stress Degradation ◽  
Enteric Coated ◽  
Uv C

Abstract A stability-indicating HPLC assay method was developed for the quantitative determination of duloxetine (DLX) in a pharmaceutical dosage form in the presence of its degradation products, and kinetic determinations were evaluated in acid conditions and UV-C radiation exposure. Chromatographic separation was achieved by use of an ACE<sup/> C18 column (250 4.0 mm id, 5 m particle size). The mobile phase was prepared by mixing aqueous 50 mM potassium phosphate buffer (pH 6.0 containing 0.3 triethylamine) and acetonitrile (60 40, v/v). DLX was rapidly degraded in an acid medium and in the presence of hydrogen peroxide and UV-C radiation; it was more stable in alkaline medium. The described method was linear over a range of 4.014.0 g/mL for determination of DLX (r = 0.9998). The precision was demonstrated by the RSD of intraday (0.791.07) and interday (0.85) studies. The mean recovery was found to be 100.56. The acid degradation of DLX in 0.1 M HCl solution showed an apparent zero-order kinetics (k = 0.177 g/mL/min), and the photodegradation demonstrated an apparent first-order kinetics (k = 0.082 g/mL/min). The developed method was found to be simple, specific, robust, linear, precise, and accurate for the determination of DLX in enteric-coated pellets.

Effect of thiol oxidation and thiol export from erythrocytes on determination of redox status of homocysteine and other thiols in plasma from healthy subjects and patients with cerebral infarction

1995 ◽  
Vol 41 (3) ◽  
pp. 361-366 ◽  
Author(s):  
A Andersson ◽  
A Lindgren ◽  
B Hultberg
Keyword(s):  
Cerebral Infarction ◽  
Healthy Subjects ◽  
Redox Status ◽  
Reduced Form ◽  
Temperature Dependent ◽  
First Order ◽  
First Order Kinetics ◽  
Before And After ◽  
Reduced Forms

Abstract Changes in concentration of reduced and oxidized low-M(r) thiols were measured in blood and plasma before and after the separation of blood cells. If centrifugation of blood was postponed, the reduced form of homocysteine in plasma increased with time at 22 degrees C; in contrast, the concentrations of other reduced thiols (cysteine, glutathione, and cysteinylglycine) decreased. In plasma the reduced forms of all thiols disappeared at a rate that followed first-order kinetics. The rates of disappearance ("half-lives") were temperature-dependent; they were about the same for glutathione and homocysteine (11.7 and 14.3 min, respectively, at 22 degrees C) and somewhat higher for cysteinylglycine and cysteine. After establishing proper sampling conditions for reduced thiols, we measured this thiol fraction as well as free (non-protein-bound) and total thiols in 10 reference subjects and 19 patients with cerebral infarction. Mild but significant hyperhomocysteinemia involving total and free homocysteine (but not reduced homocysteine) was found in the patients.

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