scholarly journals Two novel UPLC methods utilizing two different analytical columns and different detection approaches for the simultaneous analysis of velpatasvir and sofosbuvir: application to their co-formulated tablet

BMC Chemistry ◽  
2019 ◽  
Vol 13 (1) ◽  
Author(s):  
Moustapha Eid Moustapha ◽  
Rania Mohamed El-Gamal ◽  
Fathalla Fathalla Belal
Keyword(s):  
Mobile Phase ◽  
Detrimental Effect ◽  
Particle Packing ◽  
Simultaneous Analysis ◽  
Fluorescent Detection ◽  
Fluorescent Properties ◽  
Spectrophotometric Detection ◽  
Chromatographic Parameters ◽  
Theoretical Plates

Abstract In the present study two different RSLC columns, Acclaim RSLC 120 C18, 5.0 µm, 4.6 × 150 mm (column A) and Acclaim RSLC 120 C18, 2.2 µm, 2.1 × 100 mm (Column B) were utilized for the analysis of velpatasvir (VPS) in presence of sofosbuvir (SFV), where due to the encountered fluorescent properties of VPS fluorescent detection at 405 nm after excitation at 340 nm (Method 1) was used for its detection where the non-fluorescent SFV did not interfere. The same columns were further utilized for the simultaneous determination of SFV and VPS either in bulk form or in their combined tablet, where UV- spectrophotometric detection at 260 nm was selected for the simultaneous analysis of both drugs (Method 2). A mobile phase consisting of NaH2PO4, pH 2.5 (with phosphoric acid) and acetonitrile in a ratio of 60:40 v/v was used for both methods. The mobile phase was pumped at a flow rate of 1.0 mL/min when using column, A and 0.5 mL/min when using column B. The methods showed good linearity over the concentration ranges of 1.0–5.0 and 2.5–10.0 ng/mL for VPS when utilizing Method 1 A and B respectively. Where the linearity concentration range was from 30.0–150.0 to 120–600.0 ng/mL for VPS and SFV respectively when applying Method 2. Both methods 1 and 2 were performed by utilizing the two analytical columns. The different chromatographic parameters as retention time, resolution, number of theoretical plates (N), capacity factor, tailing factor and selectivity were carefully optimized. The results show that comparing the performance of the two utilized columns revealed that shorter column (2.1 mm × 100 mm) with small particle packing was superior to the longer column (4.6 × 150 mm) for the analysis of the studied drugs allowing a reduction of the analysis time by 70% without any detrimental effect on performance. This prompts the decrease of the investigation costs by saving money on organic solvents and expanding the overall number of analyses per day.

scholarly journals Validated Stability-Indicating HPLC-UV Method for Simultaneous Determination of Glipizide and Four Impurities

2011 ◽  
Vol 94 (2) ◽  
pp. 523-530 ◽  
Author(s):  
Sakshi Gupta ◽  
Gulshan Bansal
Keyword(s):  
Simultaneous Determination ◽  
Flow Rate ◽  
Retention Time ◽  
Mobile Phase ◽  
Stability Testing ◽  
Stability Indicating ◽  
Chromatographic Parameters ◽  
Interday Precision ◽  
Calculated Amount

Abstract A selective stability-indicating HPLC-UV method for simultaneous determination of glipizide and four impurities (DPs IIV) formed under hydrolytic conditions was developed and validated. The drug and impurities were resolved on an XTerra C18 column (250 4.5 mm id) in a single gradient run using buffer (0.005 M KH2PO4; pH 3.0)methanol (60 40, v/v; mobile phase A) and (20 80, v/v; mobile phase B) at a flow rate of 0.5 mL/min with 230 nm detection wavelength. The method was linear across concentration ranges of 0.2100, 0.1100, 0.5100, 0.2100, and 0.150 0000g/mL for glipizide and DPs IIV, respectively. The RSD for intraday and interday precision for the drug and impurities was <1 and <1.2, respectively. Satisfactory recoveries (96.5899.97) of each of the three concentrations selected across the linearity range of each analyte were obtained, proving the method was sufficiently accurate. The LOD was 0.07, 0.05, 0.16, 0.08, and 0.05 g/mL and the LOQ was 0.20, 0.14, 0.50, 0.23, and 0.14 g/mL for the drug and DPs IIV, respectively. Each peak was resolved with resolution of >2 from the nearest peak. Insignificant changes in retention time (<4) and calculated amount (<1.65) of drug and each impurity upon small but deliberate changes in various chromatographic parameters were observed, suggesting the method was robust. The method was applied successfully to stability testing of glipizide tablets.

scholarly journals An HPLC method for the determination of digoxin in dissolution samples

2010 ◽  
Vol 75 (11) ◽  
pp. 1583-1594 ◽  
Author(s):  
Miroslav Milenkovic ◽  
Valentina Marinkovic ◽  
Predrag Sibinovic ◽  
Radosav Palic ◽  
Dragan Milenovic
Keyword(s):  
Mobile Phase ◽  
Hplc Method ◽  
Stability Testing ◽  
Column Length ◽  
Column Temperature ◽  
Chromatographic Parameters ◽  
The Impact ◽  
Full Factorial ◽  
Phase Column

An HPLC method for digoxin quantification in dissolution samples obtained as per the official British Pharmacopeia (BP) method is presented in this paper. The chromatography was performed at 20 ?C on a Symmetry C18; 3.5 ?m, 75 x 4.6 mm column with water - acetonitrile (72 : 28, v/v), as the mobile phase and UV detection at 220 nm. The method was found to be selective, linear, accurate and precise in the specified ranges. The LOD and LOQ were 0.015 ?g mL-1 and 0.050 ?g mL-1, respectively. Robustness testing was conducted to evaluate the impact of minor changes in the chromatographic parameters (i.e., acetonitrile fraction, flow rate of the mobile phase, column temperature and column length) on the characteristics of the digoxin peak. A. full factorial design (24) was used to investigate the influence of the four variables The presented HPLC method was applied in quality and stability testing of Digoxin tablets 0.25 mg.

scholarly journals RP-LC method for simultaneous determination of sulfamethoxazole and trimethoprim content in veterinary drugs

2015 ◽  
Vol 40 (1) ◽  
pp. 32 ◽  
Author(s):  
Gabriela Padovani Tahan ◽  
Simone Caetani Machado ◽  
Evandro Conti Malaguti ◽  
Patrícia Penido Maia ◽  
Susanne Rath ◽  
...  
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Simultaneous Analysis ◽  
Ultraviolet Detector ◽  
Veterinary Medicines ◽  
Alternative Approach ◽  
Relative Standard ◽  
Water Ph ◽  
Comparison Of The Results

This study describes the development of a method for simultaneous analysis of sulfamethoxazole (SMX) and trimethoprim (TMP) through the use of high-performance liquid chromatography/ultraviolet detector, with the application to veterinary medicines. Satisfactory chromatographic separation of SMX and TMP was isocratically with a C18 column (150 x 4.6 mm, 5 mm). A mobile phase consisting of water, pH 3.5, and methanol (60:40, v/v) was delivered at a flow rate of 1.0 mL min-1 for five minutes and then, increased to 1.8 mL min-1. Detection of the drugs was performed at 213 and 230 nm. Linearity was demonstrated in the range of 5 to 70 mg mL-1 for SMX and 1 to 30 mg mL-1 for TMP (r2 ≥ 0.99 for both compounds). The relative standard deviation was ≤ 5%, and the comparison of the results with the concentrations reported on the drug labels indicated that the quantification was accurate. The resultant stressed samples were analysed by the method. The proposed method shows great potential for simultaneous analysis of the drugs evaluated and represents a new alternative approach to quality control of veterinary medicines.

Stability of cyclopiazonic acid in solution

2010 ◽  
Vol 3 (1) ◽  
pp. 25-33 ◽  
Author(s):  
G. Diaz ◽  
W. Thompson ◽  
P. Martos
Keyword(s):  
Mass Spectrometry ◽  
Formic Acid ◽  
Mobile Phase ◽  
Cyclopiazonic Acid ◽  
Tandem Mass ◽  
Considerable Difficulty ◽  
Ambient Oxygen ◽  
Carry Over ◽  
Chromatographic Parameters

Cyclopiazonic acid (CPA) is an important mycotoxin given its toxicity and prevalence in foods and feeds. There is tremendous interest in developing analytical methods that include CPA as part of a multi-residue mycotoxin routine, but there appears to be considerable difficulty in analysing it using liquid chromatography with electrospray ionisation tandem mass spectrometry (LC-MS/MS). During the development of a multi-residue method for mycotoxins including CPA, a number of issues were discovered under routine and common analytical conditions that have an impact on the determination of CPA, including: (1) at the ng/ml level CPA reacts with ambient oxygen from the headspace of the vial, an effect that decreases its concentration linearly; (2) CPA readily adsorbs to plastic in a reversible fashion; (3) CPA is acid hydrolysed with formic acid; (4) CPA reacts with the column stationary phase affecting chromatographic parameters; and (5) CPA presents significant carry-over issues. In an effort to find solutions to these problems we found that CPA can be protected from reacting with oxygen by adding 1 µg/ml ascorbic acid and that its carry-over can be reduced to a negligible level by injecting ammonia between injections of solutions containing CPA, even with formic acid in the mobile phase. Chromatographic conditions for CPA have been optimised in consideration of all of the aforementioned concerns.

A micromethod for quantitative determination of iodoamino acids in thyroglobulin

1997 ◽  
Vol 153 (1) ◽  
pp. 99-104 ◽  
Author(s):  
N Baudry ◽  
B Mallet ◽  
P J Lejeune ◽  
L Vinet ◽  
J L Franc
Keyword(s):  
Acetic Acid ◽  
Enzymatic Hydrolysis ◽  
Mobile Phase ◽  
High Sensitivity ◽  
The Other ◽  
Reverse Phase Hplc ◽  
Reverse Phase ◽  
Spectrophotometric Detection ◽  
Hydrolysis Of

Abstract We describe a new method for quantification of iodoamino acids after enzymatic hydrolysis of thyroglobulin. The procedure involves separation of monoiodotyrosine (MIT), diiodotyrosine, tri-iodothyronine and thyroxine by reverse phase HPLC with a Vydac C18 stationary phase and a mobile phase of water–acetonitrile–acetic acid. The separation is monitored by sensitive spectrophotometric detection through a 96-well microplate system based on the catalytic Sandell–Kolthoff reaction of iodide on the oxidation of arsenic(III) by cerium(IV). This new microassay is particularly convenient because of its high sensitivity and its rapidity (less than 2 h). It can detect 1 pmol MIT and 0·5 pmol of the other three iodoamino acids with a recovery higher than 96%. Moreover, the 96-well microplate system allows many samples to be tested simultaneously and avoids the use of radiolabeled iodine. Journal of Endocrinology (1997) 153, 99–104

scholarly journals Development and validation of an LC-MS/MS method for the determination of adapalene in pharmaceutical forms for skin application

2016 ◽  
Vol 81 (10) ◽  
pp. 1171-1181 ◽  
Author(s):  
Vladimir Dobricic ◽  
Natasa Bubic-Pajic ◽  
Bojan Markovic ◽  
Sote Vladimirov ◽  
Snezana Savic ◽  
...  
Keyword(s):  
Mobile Phase ◽  
Ammonium Acetate ◽  
Intermediate Precision ◽  
Column Temperature ◽  
Mobile Phases ◽  
Relative Standard ◽  
Liquid Chromatography Tandem Mass ◽  
Chromatographic Parameters ◽  
Development And Validation

Development and validation of a liquid chromatography - tandem mass spectrometry (LC-MS/MS) method for the determination of adapalene in pharmaceutical forms for skin application were presented. The MS/MS analysis of adapalene was performed by use of three mobile phases, consisted of acetonitrile and (a) 0.1 % formic acid, (b) 0.1 % trifluoroacetic acid and (c) 20 mM ammonium acetate. The strongest signals of parent ion and dominant product ion were obtained in negative mode by use of the mobile phase (c). Validation of this method was performed according to the ICH guidelines. Small variations of selected chromatographic parameters (concentration of ammonium acetate, mobile phase composition, column temperature and flow rate) did not affect qualitative and quantitative system responses significantly, which proved method?s robustness. The method is specific for the determination of adapalene. Linearity was proved in the concentration range 6.7 - 700.0 ng mL-1 (r = 0.9990), with limits of detection and quantification 2.0 ng mL-1 and 6.7 ng mL-1, respectively. Accuracy was confirmed by calculated recoveries (98.4 % - 101.5 %). Precision was tested at three levels: injection repeatability, analysis repeatability and intermediate precision. Calculated relative standard deviations were less than 1, 2 and 3 %, respectively.

Effects of Injection Solvent and Mobile Phase on Efficiency in Reverse-Phase Liquid Chromatographic Determination of Aflatoxin M1

1990 ◽  
Vol 73 (1) ◽  
pp. 69-70 ◽  
Author(s):  
Rodney W Beaver
Keyword(s):  
Mobile Phase ◽  
Chromatographic Determination ◽  
Aflatoxin M1 ◽  
Mobile Phase Composition ◽  
Reverse Phase ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic ◽  
Theoretical Plates

Abstract The effects of Injection solvent and mobile phase composition on the reverse-phase liquid chromatographic determination of aflatoxin M1 (M1) were examined. M1 was converted to the more highly fluorescent derivative aflatoxin M2a (M2a)- Using a C-18 column and a mobile phase of H20-MeCNMeOH (60 + 20 + 20) (MP-A), M2a was dissolved in various ratios of MeCN-H20 prior to Injection. Chromatographic efficiency for the M2a peak varied from ca 2000 theoretical plates when injected in 30% aqueous MeCN to ca 9000 plates when injected in water alone. However, using the same C-18 column but with a mobile phase of H20-IPAMeCN (80 + 12 + 8) (MP-B), the M2a peak exhibited 25000 plates when injected in 30% aqueous MeCN and 10000 plates when injected in water alone.

scholarly journals Determination of Rocuronium bromide by hydrophilic interaction liquid chromatography (HILIC)

2001 ◽  
Vol 57 ◽  
pp. 17-24 ◽  
Author(s):  
Natalija Nakov ◽  
Rumenka Petkovska ◽  
Liljana Ugrinova ◽  
Suzana Trajkovic-Jolevska ◽  
Aneta Dimitrovska
Keyword(s):  
Liquid Chromatography ◽  
Mobile Phase ◽  
Ph Value ◽  
Degradation Products ◽  
Hydrophilic Interaction Liquid Chromatography ◽  
Hydrophilic Interaction ◽  
Rocuronium Bromide ◽  
Silica Column ◽  
Chromatographic Parameters

A new method involving hydrophilic interaction liquid chromatography (HILIC) has been developed for determination of rocuronium bromide in presents of its main impurities (impurity A and impurity C), which are also its main degradation products, in solution for injection. The influence of the critical chromatographic parameters such as content of acetonitrile in the mobile phase, ionic strength and pH value of the buffer used in the mobile phase were investigated using the Design of experiments approach (DoE). The mechanism of retention of rocuronium bromide on bare silica column was also investigated. Optimal chromatographic conditions were obtained using mixture of acetonitrile and ammonium formate (107.5mM, pH 7.0) in ratio 90:10 as a mobile phase. The validation results have shown that the method is suitable for determination of rocuronium bromid in solution for injection.

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