scholarly journals Study of the Oxidative Forced Degradation of Glutathione in Its Nutraceutical Formulations Using Zone Fluidics and Green Liquid Chromatography

Separations ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 16
Author(s):  
Apostolia Tsiasioti ◽  
Constantinos K. Zacharis ◽  
Anastasia-Stella Zotou ◽  
Paraskevas D. Tzanavaras
Keyword(s):  
Reversed Phase ◽  
Hplc Method ◽  
Forced Degradation ◽  
Oxidized Glutathione ◽  
Reversed Phase Hplc ◽  
First Order ◽  
Direct Uv Detection ◽  
First Order Kinetics ◽  
Time Period ◽  
Pseudo First Order

In the present study, we report the results of our investigation of the oxidative forced degradation of glutathione in its nutraceutical formulations by two validated analytical methods. The first is based on the reaction of glutathione with o-phthalaldehyde through an automated zone fluidics flow platform and fluorimetric detection (λex/λem = 340/425 nm). The second is based on the separation of glutathione and its oxidation product by a green reversed-phase HPLC method coupled to direct UV detection, at 210 nm. A solution of 3% w/v H2O2 provided fast oxidation of more than 95% of glutathione to yield oxidized glutathione in a time period of 180 min. The mechanism of the oxidation was proved to follow pseudo-first order kinetics. The k, t90 and t1/2 values were calculated.

In-vitro Kinetic Hydrolysis Study of Metronidazole Derivatives with Carvacrol and Eugenol Using Validated RP-HPLC Method

2020 ◽  
Vol 16 ◽  
Author(s):  
M. Alarjah
Keyword(s):  
Half Life ◽  
Hplc Method ◽  
Hydrolysis Rate ◽  
First Order ◽  
First Order Kinetics ◽  
Rp Hplc ◽  
Pharmacokinetic Properties ◽  
Pseudo First Order ◽  
Kinetic Hydrolysis

Background: Prodrugs principle is widely used to improve the pharmacological and pharmacokinetic properties of some active drugs. Much effort was made to develop metronidazole prodrugs to enhance antibacterial activity and or to improve pharmacokinetic properties of the molecule or to lower the adverse effects of metronidazole. Objective: In this work, the pharmacokinetic properties of some of monoterpenes and eugenol pro metronidazole molecules that were developed earlier were evaluated in-vitro. The kinetic hydrolysis rate constants and half-life time estimation of the new metronidazole derivatives were calculated using the validated RP-HPLC method. Method: Chromatographic analysis was done using Zorbbax Eclipse eXtra Dense Bonding (XDB)-C18 column of dimensions (250 mm, 4.6 mm, 5 μm), at ambient column temperature. The mobile phase was a mixture of sodium dihydrogen phosphate buffer of pH 4.5 and methanol in gradient elution, at 1ml/min flow rate. The method was fully validated according to the International Council for Harmonization (ICH) guidelines. The hydrolysis process carried out in an acidic buffer pH 1.2 and in an alkaline buffer pH 7.4 in a thermostatic bath at 37ºC. Results: The results followed pseudo-first-order kinetics. All metronidazole prodrugs were stable in the acidic pH, while they were hydrolysed in the alkaline buffer within a few hours (6-8 hr). The rate constant and half-life values were calculated, and their values were found to be 0.082- 0.117 hr-1 and 5.9- 8.5 hr., respectively. Conclusion: The developed method was accurate, sensitive, and selective for the prodrugs. For most of the prodrugs, the hydrolysis followed pseudo-first-order kinetics; the method might be utilised to conduct an in-vivo study for the metronidazole derivatives with monoterpenes and eugenol.

scholarly journals Quantitative determination of clobetasone butyrate in bulk and cream formulation by a validated stability-indicating reversed-phase HPLC method

2018 ◽  
Vol 9 (2) ◽  
pp. 92-98
Author(s):  
Hassan Ahmad Alhazmi ◽  
Gunasekar Manoharan ◽  
Mohammed Al Bratty ◽  
Sadique Akhtar Javed
Keyword(s):  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Reversed Phase ◽  
Hplc Method ◽  
Forced Degradation ◽  
Reversed Phase Hplc ◽  
Stability Indicating ◽  
Cream Formulation ◽  
Relative Standard ◽  
Effluent Flow Rate

A simple isocratic reversed-phase HPLC method for quantification of clobetasone in bulk and cream dosage forms has been developed. Chromatographic analysis was accomplished on an C18 column utilizing a mixture of methanol and water (84:16 v:v, pH = 6.0) as mobile phase. An effluent flow rate of 1 mL/min was adjusted and the detection was made at 240 nm wavelength. The method was evaluated according to ICH guidelines Q2 R1 for linearity, specificity, sensitivity, precision and accuracy. The method exhibited good linearity with correlation coefficient (r2) of 0.9993 over the concentration range from 5 to 50 μg/mL. The recoveries of the test drug from the cream sample was found to be 98.56 to 99.51% and the limit of detection and quantification were calculated as 0.85 and 2.83 μg/mL, respectively, suggesting the accuracy and sensitivity of the developed method. The precision was demonstrated by a low percentage of relative standard deviation (<1%) from six independent assay analysis performed for the cream formulation. Stability indicating property of the proposed method was demonstrated by performing the analysis of forced degradation samples. The developed method can be used for estimation of the clobetasone butyrate in bulk and pharmaceutical formulations for routine analysis in the quality control laboratories.

scholarly journals VALIDATION OF A SIMPLE REVERSED PHASE-HPLC METHOD FOR THE DETERMINATION OF BACLOFEN IN TABLETS

2018 ◽  
Vol 2 (2) ◽  
pp. 37-43
Author(s):  
Juliana Dos Santos ◽  
Priscila Rosa ◽  
Andréa Inês Horn Adams
Keyword(s):  
Spinal Cord Injuries ◽  
Reversed Phase ◽  
Hplc Method ◽  
Forced Degradation ◽  
Reversed Phase Hplc ◽  
Waste Generation ◽  
Degradation Study ◽  
The Cost ◽  
Current Guidelines

Baclofen is a muscle relaxant used as a first option to treat spasticity and muscle spasms in patients with spinal cord injuries, which is available in Brazil as 10 mg tablets. The compendia methods employ HPLC by ion pairing that requires the use of specific reagents and column conditioning, increasing the waste generation and the cost of analysis. In this study, an isocratic, simple and stability-indicating HPLC method was validated to assay baclofen tablets. A C-18 column (Luna®, 150 x 4.6 mm, 5μm), mobile phase composed by triethylamine 10 mM pH 7.0, methanol and acetonitrile (80:15:5), flow rate 1 mL/min and detection at 220 nm was used. The baclofen retention time was 6.2 min and the method was linear in the range of 5 – 100 μg.mL-1 (r = 0.9999). Method selectivity was demonstrated by the forced degradation study and simultaneous analysis of baclofen impurity. The method showed accuracy (mean recovery 99.27%) and precision (RSD < 2%). The robustness was evaluated by factorial design, and the method was robust robust regarding the proposed variations. The developed method met the requirement of current guidelines, being indicative of stability and suitable for the determination of baclofen in tablets.

Determination of 5-hydroxymethyl-2-furaldehyde in royal jelly by a rapid reversed phase HPLC method

2013 ◽  
Vol 5 (19) ◽  
pp. 5010 ◽  
Author(s):  
Marco Ciulu ◽  
Roberta Farre ◽  
Ignazio Floris ◽  
Valeria M. Nurchi ◽  
Angelo Panzanelli ◽  
...  
Keyword(s):  
Royal Jelly ◽  
Reversed Phase ◽  
Hplc Method ◽  
Reversed Phase Hplc

scholarly journals Simultaneous Determination of Preservatives (Methyl Paraben and Propyl Paraben) in Sucralfate Suspension Using High Performance Liquid Chromatography

2011 ◽  
Vol 8 (1) ◽  
pp. 340-346 ◽  
Author(s):  
Rajesh M. Kashid ◽  
Santosh G. Singh ◽  
Shrawan Singh
Keyword(s):  
High Performance Liquid Chromatography ◽  
Simultaneous Determination ◽  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Hplc Method ◽  
Reversed Phase Hplc ◽  
Methyl Paraben ◽  
Propyl Paraben

A reversed phase HPLC method that allows the separation and simultaneous determination of the preservatives methyl paraben (M.P.) and propyl paraben (P.P.) is described. The separations were effected by using an initial mobile phase of water: acetonitrile (50:50) on Inertsil C18 to elute P.P. and M.P. The detector wavelength was set at 205 nm. Under these conditions, separation of the two components was achieved in less than 10 min. Analytical characteristics of the separation such as precision, specificity, linear range and reproducibility were evaluated. The developed method was applied for the determination of preservative M.P. and P.P. at concentration of 0.01 mg/mL and 0.1 mg/mL respectively. The method was successfully used for determining both compounds in sucralfate suspension.

FORCED DEGRADATION STUDIES OF OLMESARTAN MEDOXOMIL AND CHLORTHALIDONE: DEVELOPMENT AND VALIDATION OF STABILITY-INDICATING RP‑HPLC METHOD

INDIAN DRUGS ◽  
2019 ◽  
Vol 56 (03) ◽  
pp. 39-45
Author(s):  
A Sherje ◽  
A. Sonalkar ◽  
Keyword(s):  
High Performance ◽  
Dosage Form ◽  
Olmesartan Medoxomil ◽  
The United States ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Forced Degradation ◽  
Uv Detector ◽  
Tablet Dosage

A reversed-phase high-performance liquid chromatographic method was developed for the simultaneous determination of olmesartan medoxomil (OLME) and chlorthalidone (CHLOR) in tablet dosage form. The analysis was performed on Inertsil ODS C18 (250 x 4.6 mm, 5 μ) using KH2PO4 phosphate buffer (pH) and acetonitrile as mobile phase in the proportion of 60: 40 v/v at flow rate of 1.0 mL/min. Detection of drugs was carried out in isocratic mode using UV detector at 275 nm. The retention time of OLME and CHLOR was 13.9 ± 0.1 min. and 4.4 ± 0.5 min., respectively and the total run time was 20 min. The method was validated according to the requirements of the United States Pharmacopeia. The percentage recoveries was found to be in the range of 98.9 - 100.7%. The method was successfully applied to the assay of OLME and CHLOR in tablet dosage form.

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.

A tandem solid phase extraction, reversed-phase HPLC method for determining SDZ WAG 994 in dog, monkey and rat blood

1997 ◽  
Vol 15 (6) ◽  
pp. 749-758 ◽  
Author(s):  
Jeffrey A. Cramer ◽  
Susan J. Pasternak ◽  
Lawrence V. Athill
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Reversed Phase ◽  
Hplc Method ◽  
Phase Extraction ◽  
Reversed Phase Hplc ◽  
Rat Blood
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