scholarly journals Retention Modelling of Phenoxy Acid Herbicides in Reversed-Phase HPLC under Gradient Elution

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1262 ◽  
Author(s):  
Alessandra Biancolillo ◽  
Maria Anna Maggi ◽  
Sebastian Bassi ◽  
Federico Marini ◽  
Angelo Antonio D’Archivio
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Retention Factor ◽  
Reversed Phase ◽  
Model Complexity ◽  
Retention Data ◽  
Rp Hplc ◽  
Phenoxy Acid Herbicides ◽  
Acid Herbicides ◽  
Phenoxy Acids

Phenoxy acid herbicides are used worldwide and are potential contaminants of drinking water. Reversed phase high-performance liquid chromatography (RP-HPLC) is commonly used to monitor phenoxy acid herbicides in water samples. RP-HPLC retention of phenoxy acids is affected by both mobile phase composition and pH, but the synergic effect of these two factors, which is also dependent on the structure and pKa of solutes, cannot be easily predicted. In this paper, to support the setup of RP-HPLC analysis of phenoxy acids under application of linear mobile phase gradients we modelled the simultaneous effect of the molecular structure and the elution conditions (pH, initial acetonitrile content in the eluent and gradient slope) on the retention of the solutes. In particular, the chromatographic conditions and the molecular descriptors collected on the analyzed compounds were used to estimate the retention factor k by Partial Least Squares (PLS) regression. Eventually, a variable selection approach, Genetic Algorithms, was used to reduce the model complexity and allow an easier interpretation. The PLS model calibrated on the retention data of 15 solutes and successively tested on three external analytes provided satisfying and reliable results.

scholarly journals Development and validation of reversed phase high performance liquid chromatography (RP-HPLC) for quantification of captopril in rabbit plasma

2020 ◽  
Author(s):  
Muhammad Fawad Rasool ◽  
Umbreen Fatima Qureshi ◽  
Nazar Muhammad Ranjha ◽  
Imran Imran ◽  
Mouqadus Un Nisa ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Reversed Phase ◽  
Rabbit Plasma ◽  
Rp Hplc ◽  
Relative Standard

AbstractTh accurate rapid, simple and selective reversed phase high performance liquid chromatography (RP-HPLC) has been established and validated for the determination of captopril (CAP). Chromatographic separation was accomplished using prepacked ODSI C18 column (250 mm × 4.6 mm with 5 μm particle size) in isocratic mode, with mobile phase consisting of water: acetonitrile (60:40 v/v), pH adjusted to 2.5 by using 85% orthophosphoric acid at a flow rate of 1 mL/min and UV detection was performed at 203 nm. RP-HPLC method used for the analysis of CAP in mobile phase and rabbit plasma was established and validated as per ICH-guidelines. It was carried out on a well-defined chromatographic peak of CAP was established with a retention time of 4.9 min and tailing factor of 1.871. The liquid–liquid extraction method was used for extraction of CAP from the plasma. Excellent linearity (R2 = 0.999) was shown over range 3.125–100 µg/mL with mean percentage recoveries ranges from 97 to 100.6%. Parameters of precision and accuracy of the developed method meet the established criteria. Intra and inter-day precision (% relative standard deviation) study was also performed which was less than 2% which indicate good reproducibility of the method. The limit of detection (LOD) and quantification for the CAP in plasma were 3.10 and 9.13 ng/mL respectively. The method was suitably validated and successfully applied to the determination of CAP in rabbit plasma samples.

scholarly journals Enantioselective HPLC Analysis to Assist the Chemical Exploration of Chiral Imidazolines

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 640 ◽  
Author(s):  
Bruno Cerra ◽  
Antonio Macchiarulo ◽  
Andrea Carotti ◽  
Emidio Camaioni ◽  
Ina Varfaj ◽  
...  
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Hplc Analysis ◽  
Water Solubility ◽  
Pearson Correlation ◽  
Retention Factor ◽  
Reversed Phase ◽  
Base Line ◽  
Structure Property ◽  
Organic Modifiers

In the present work, we illustrate the ability of high-performance liquid chromatography (HPLC) analysis to assist the synthesis of chiral imidazolines within our medicinal chemistry programs. In particular, a Chiralpak® IB® column containing cellulose tris(3,5-dimethylphenylcarbamate) immobilized onto a 5 μm silica gel was used for the enantioselective HPLC analysis of chiral imidazolines synthesized in the frame of hit-to-lead explorations and designed for exploring the effect of diverse amide substitutions. Very profitably, reversed-phase (RP) conditions succeeded in resolving the enantiomers in nine out of the 10 investigated enantiomeric pairs, with α values always higher than 1.10 and RS values up to 2.31. All compounds were analysed with 50% (v) water while varying the content of the two organic modifiers acetonitrile and methanol. All the employed eluent systems were buffered with 40 mM ammonium acetate while the apparent pH was fixed at 7.5. Based on the experimental results, the prominent role of π-π stacking interactions between the substituted electron-rich phenyl groups outside of the polymeric selector and the complementary aromatic region in defining analyte retention and stereodiscrimination was identified. The importance of compound polarity in explaining the retention behaviour with the employed RP system was readily evident when a quantitative structure-property relationship study was performed on the retention factor values (k) of the 10 compounds, as computed with a 30% (v) methanol containing mobile phase. Indeed, good Pearson correlation coefficients of retention factors (r - log k1st = −0.93; r - log k2nd = −0.94) were obtained with a water solubility descriptor (Ali-logS). Interestingly, a n-hexane/chloroform/ethanol (88:10:2, v/v/v)-based non-standard mobile phase allowed the almost base-line enantioseparation (α = 1.06; RS = 1.26) of the unique compound undiscriminated under RP conditions.

scholarly journals ANALYTICAL QUALITY-BY-DESIGN (AQBD) APPROACH FOR THE DEVELOPMENT AND VALIDATION OF RP-HPLC METHOD FOR THE ESTIMATION OF LAMOTRIGINE IN BULK AND TABLET FORMULATION

2021 ◽  
Vol 10 (5) ◽  
pp. 3591-3596
Author(s):  
Manisha P. Puranik
Keyword(s):  
Flow Rate ◽  
Mobile Phase ◽  
High Performance ◽  
Quality By Design ◽  
Active Pharmaceutical Ingredient ◽  
Reversed Phase ◽  
Hplc Method ◽  
Analytical Technique ◽  
Rp Hplc ◽  
Ich Guideline

The current analytical exploration illustrated developing a reversed-phase high-performance liquid chromatography (RP-HPLC) technique and consequent substantiation for analyzing lamotrigine (LAM) active pharmaceutical ingredient (API) using a Quality-by-design (QbD) approach (Central Composite Design), in bulk product as well as in the tablet formulations. In this experiment, based on systematic scouting, four key components (viz., mobile phase, column, flow-rate, and wavelength) were studied by the RP-HPLC method. 13 experimental runs were done with acetonitrile (ACN) (40-60% v/v) having flow-rate in the range 0.8 mL/min to 1.2 mL/min. The proposed analytical method was thoroughly corroborated in terms of ruggedness linearity, robustness, accuracy, and precision in accordance with ICH guideline Q2A and ICH guideline Q2B. Under the optimum chromatographic environment; Intersil C8 column of 250 mm length, 4.6 mm (i.d.); 20 μL injection volume; and mobile phase ACN: Methanol (60:40 v/v), a retention time of 2.542 min was noticed at 220 nm detection wavelength. The method was found to be extremely reproducible, accurate, linear, precise, robust, and economically adequate to execute the estimation. The intended analytical technique was thoroughly assessed through statistical tools and could be an imperative concern for the habitual scrutiny of LAM in bulk products and its formulation.

scholarly journals DEVELOPMENT AND VALIDATION OF REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY METHOD FOR GABAPENTIN AND ITS RELATED SUBSTANCES IN CAPSULE DOSAGE FORM AND EXCIPIENT COMPATIBILITY STUDIES

2018 ◽  
Vol 11 ◽  
Author(s):  
Afroz Patan
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Dosage Form ◽  
Reversed Phase ◽  
Hplc Method ◽  
Compatibility Studies ◽  
Compound A ◽  
Related Substances ◽  
Rp Hplc ◽  
Excipient Compatibility

Objective: A simple, accurate, precise, and reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for gabapentin (GBP) and its related substances in the capsule dosage form and excipient compatibility studies. Methods: The review of literature indicates that various methods have been reported for the estimation of GBP. When some excipients were used for GBP, it produced degradation product called lactam due to the presence of more water content. Hence, a novel RP-HPLC method has been developed for studying excipient compatibility and related substances of GBP in capsule dosage form using excipients such as lactose anhydrous and dried maize starch which is having less water activity. Waters Alliance e2695 separation module with ultraviolet/photodiode array (UV/PDA) detector with Inertsil C8 (250 mm×4.6 mm); 5 μm with an injection volume of 50 μl is injected and eluted with the (gradient program) mobile Phase A buffer: acetonitrile (940:60) and mobile phase B buffer: acetonitrile (700:300) pH 6.9 with 5 N potassium hydroxide which is pumped at a speed of 1.5 ml/min and detected by UV/PDA detector at 210 nm. The peaks of GBP and GBP-related compound A are well separated at 6.7 min and 34.5 min, respectively. Results: The method developed was approved for various parameters such as accuracy, specificity, precision, intermediate precision, range, linearity, robustness, limit of detection, limit of quantification, steadiness, and system suitability according to the International Conference on Harmonization guidelines. The results got were according to the acceptance criteria. Conclusion: The technique proposed was assured for detection of related substances in the marketed formulation and could be used for the routine analysis of GBP and GBP-related compound A in the capsule dosage form.

Separation of Tegafur and its Impurities by Reversed-Phase High-Perfomance Liquid Chromatography

2014 ◽  
Vol 52 (1-2) ◽  
pp. 54-60
Author(s):  
O. Rotkaja ◽  
J. Golushko ◽  
K. Kuprevics
Keyword(s):  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Good Description ◽  
Retention Factor ◽  
Reversed Phase ◽  
Chromatographic Behavior ◽  
Optimum Conditions ◽  
Factor Log ◽  
Acetonitrile Concentration

Abstract The chromatographic behavior of tegafur and its impurities on a naphthalene Cosmosil piNAP column under reversed-phase high-performance liquid chromatography conditions was examined. A good description of the retention was achieved through the application of statistical weights to the widely used quadratic relationships between the logarithm of the retention factor (log k) and the organic solvent concentration in the mobile phase. Optimum conditions for isocratic separation of the compounds were found with acetonitrile concentration of 10-30% in the mobile phase

scholarly journals Effect of 1,2,4-triazole derivatives structure on their sorption by hypercarb under RP HPLC conditions

2019 ◽  
Vol 59 (7) ◽  
pp. 76-84
Author(s):  
Yulia P. Kurnysheva ◽  
◽  
Semen A. Ryzhkin ◽  
Svetlana V. Kurbatova ◽  
◽  
...  
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Retention Factor ◽  
Effect Of Temperature ◽  
Bulk Solution ◽  
Molecular Volume ◽  
Chromatographic Retention ◽  
Triazole Derivatives ◽  
Rp Hplc ◽  
Sorption Characteristics

The results of 1,2,4-triazole derivatives studies by high-performance liquid chromatography using water-acetonitrile mixture in various volume ratios as eluent are presented. A porous graphitic carbon – hypercarb was used as a sorbent. It has been shown that the main physicochemical parameters determining the sorption of 1,2,4-triazole derivatives under the conditions of RP HPLC are the lipophilicity, polarizability and the volume of analyte molecules. At the same time, almost all the investigated substances are relatively polar, which contributes to their interaction with the components of the polar mobile phase. In general, among the derivatives of 1,2,4-triazole selected for the study, the values of the molecular volume, polarizability, lipophilicity and dipole moment vary within relatively wide limits, which leads to significant differences in the sorption characteristics of these compounds, which are also determined by the nature of the sorbent. At the same time, a symbiotic relationship was established in changing the values of the retention factor of the studied substances, their polarizability and lipophilicity. The observed deviations from the dependences obtained are due to specific interactions of sorbate molecules with the components of the mobile phase. The effect of temperature on the chromatographic retention of azoles was investigated. The sorption isotherm of 2-(1H-triazol-1-ylmethyl) phenol is obtained, which is almost linear in the initial part, which corresponds to the Henry region. The thermodynamic sorption characteristics of triazole derivatives have been experimentally determined. It is established that the values of changes in standard molar enthalpy and Gibbs energy of sorption during the transition of the molecules of the analyzed analytes from the bulk solution to the surface layer of the hypercarb are predominantly negative, which indicates the exothermic process and its spontaneous flow. At the same time, these values lie in a relatively narrow range and are determined mainly by the nature of the substituent and its position in the heterocycle.

scholarly journals Simultaneous determination of chlorpheniramine maleate, phenylephrine hydrochloride, paracetamol and caffeine in pharmaceutical preparation by RP-HPLC

2013 ◽  
Vol 19 (1) ◽  
pp. 57-65 ◽  
Author(s):  
V.K. Redasani ◽  
A.P. Gorle ◽  
R.A. Badhan ◽  
P.S. Jain ◽  
S.J. Surana
Keyword(s):  
Simultaneous Determination ◽  
Mobile Phase ◽  
High Performance ◽  
Pharmaceutical Preparation ◽  
Reversed Phase ◽  
Chlorpheniramine Maleate ◽  
Phenylephrine Hydrochloride ◽  
Rp Hplc ◽  
Relative Standard

Reversed-phase High-Performance Liquid-Chromatography (RP-HPLC) method was successfully developed for the simultaneous determination of quaternary mixture consisting of chlorpheniramine maleate (CPM), phenylephrine hydrochloride (PE), paracetamol (PCM) and caffeine in pharmaceutical preparation. The method was found to be simple, sensitive and rapid. The separation of the drugs was carried out using Inertsil ODS C18 column using 0.05M dibasic phosphate buffer: acetonitrile (93: 07; v/v) as mobile phase. The flow rate of mobile phase was adjusted to 1.5 ml/min and column oven temperature was kept at 30?C. All these drugs were resolved successfully with retention times 2.74 (CPM), 3.48(PE), 9.5(PCM) and 26.32(Caffeine) minutes when detection was carried out at 215 nm. Correlation coefficient was found 0.999, 0.998, 0.999 and 0.999 respectively for CPM, PE, PCM and Caffeine. The relative standard deviation in the tablets was found less than 2% for six replicates. The method was validated for precision and accuracy. Thus, proposed method can be successfully applicable to the pharmaceutical preparation containing the above mentioned drugs without any interference of excipients.

STUDIES ON HPTLC AND RP-HPLC METHODS FOR DETERMINATION OF TADALAFIL IN PHARMACEUTICAL DOSAGE FORM

INDIAN DRUGS ◽  
2016 ◽  
Vol 53 (01) ◽  
pp. 38-46
Author(s):  
Z. G Khan ◽  
◽  
S. J. Surana ◽  
A. A. Shirkhedkar
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Dosage Form ◽  
Enzyme Inhibitor ◽  
Reversed Phase ◽  
Pharmaceutical Dosage Form ◽  
Aluminum Sheets ◽  
Rp Hplc ◽  
Phosphodiesterase Type

Tadalafil is a selective phosphodiesterase Type 5 enzyme inhibitor. Simple and sensitive High Performance Thin - Layer Chromatography (HPTLC) and Reversed - Phase High - Performance Liquid Chromatography (RP-HPLC) methods have been developed for estimation of tadalafil in pharmaceutical dosage form. Separation of tadalafil was achieved on HPTLC aluminum sheets of silica gel 60 F254 with mixture of toluene: methanol (7.2: 2.8 V/V) as the mobile phase. tadalafil obeyed linearity in the concentration range of 300 - 800 ng/band with correlation coefficient (r2) 0.9994. Detection was performed densitometricaly at 284 nm with Rf 0.50 ± 0.02. RP-HPLC separation was achieved using Qualisil C18 column on mixture of methanol: water (75: 25 % V/V) as the mobile phase. Linearity was plotted in range of 2 – 12 μg/mL and (r2) value as 0.9998. The retention time was found to be 4.82 ± 0.02 min. The developed HPTLC and RP-HPLC methods have been successfully applied for the determination of tadalafil in bulk and pharmaceutical formulation. Both these methods were statistically compared.

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