scholarly journals Studying the suitability of hybrid micelle liquid chromatography for estimating the lipophilicity of some partial dopamine agonists used to attain the reward circuit

2021 ◽  
Vol 8 (5) ◽  
pp. 202371
Author(s):  
M. E. K. Wahba ◽  
D. El Wasseef ◽  
D. El Sherbiny

Three micellar-based mobile phases were developed and optimized for the simultaneous determination of certain partial dopamine agonists that are used to overcome the withdrawal symptoms of abused drugs, namely aripiprazole, pramipexole and piribedil. The studied drugs were separated using micellar liquid chromatography, hybrid micellar liquid chromatography (HMLC) and microemulsion liquid chromatography (MELC). The three developed mobile phases were studied to estimate their suitability for the measurement of log p -values of the studied drugs. Experimental determination of log P m/w values using the three mobile phases demonstrates that HMLC is the mobile phase of choice since the obtained practical log P m/w values were in accordance with the reported log P values, and calculated log P and log D values. An explanation of the obtained results was presented based on the separation retention mechanism for each chromatographic technique. Furthermore, the effect of the pH and the column temperature in HMLC on the practical log P m/w values was studied. To verify its suitability for experimental measurement of log P m/w  , HMLC was subjected to full validation according to the United States Pharmacopeia.

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Danielle Cristina da Silva ◽  
Cláudio Celestino Oliveira

Method for extraction and determination of amoxicillin, caffeine, ciprofloxacin, norfloxacin, tetracycline, diclofenac, ibuprofen, nimesulide, levonorgestrel, and 17α-ethynylestradiol exploiting micellar liquid chromatography with PDA detector and solid-phase extraction was proposed. The usage of toxic solvents was low; the chromatographic separation of the medicaments was performed using a C18 column and mobile phases A and B containing 15.0% (v/v) ethanol, 3.0% (m/v) sodium dodecyl sulfate (SDS), and 0.02 mol·L−1 phosphate at pHs 7.0 and 8.0, respectively. The method is simple, selective, and fast, and the analytes were separated in 23.0 min. For extraction, 1000 mL of sample containing 2.0% (v/v) ethanol and 0.002 mol·L−1 citric acid at pH 2.50 was loaded through a 1000 mg of C18 cartridge. The analytes were eluted using 3.0 mL of ethanol, which were evaporated and redissolved in 0.5 mL of mobile phase. Concentration factors better than 1200, except amoxicillin (224), were obtained. The analytical curves were linear (R2 better than 0.992); LOD and LOQ n=10 presented values in the range of 0.019–0.247 and 0.058–0.752 mg·L−1, respectively. Recoveries of 99% were obtained, and the results are in agreement with those obtained by the comparative methods.


2020 ◽  
Vol 16 (6) ◽  
pp. 690-697
Author(s):  
Yuedong Yang ◽  
Hao Zhi ◽  
Baofei Yan ◽  
Yi Tian ◽  
Jianping Shen ◽  
...  

Background: The simultaneous determination of multiple components in a sample is an important factor in the quality control of traditional Chinese medicines and can give an indication of potential clinical applications. Introduction: A rapid and sensitive method has been introduced for the simultaneous quantitative analysis of eight bioactive flavonoid constituents from Scutellariae Radix using ultra-high performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry. Methods: The separation was performed on a Waters Acquity UPLC C18 column (2.1 mm×100 mm, 1.7 μm), under optimized mass spectrometry conditions, with a flow rate of 0.3 mL/min. The column temperature was maintained at 35°C and the injection volume was 3 μL. Results: The method showed a good linear relationship of each component; all R2 values were above 0.9990 in the experiment. The RSDs of the precision test, repeatability test, stability test and recovery test were all not more than 2.86 %. We found that the total percentage amounts of the eight flavonoids were 22.19%, 18.63% and 10.86% in Raw Scutellariae Radix (RSR), Wine Scutellaria Radix (WSR) and Scutellaria Radix Charcoal (SRC) respectively. Conclusion: The method was successfully applied to the simultaneous determination of the eight bioactive flavonoids of Raw Scutellariae Radix, Wine Scutellaria Radix and Scutellaria Radix Charcoal.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Irena Malinowska ◽  
Katarzyna E. Stępnik

Micellar liquid chromatography (MLC) with the use of high performance liquid chromatography (HPLC) was used to determine some physicochemical parameters of six biogenic amines: adrenaline, dopamine, octopamine, histamine, 2-phenylethylamine, and tyramine. In this paper, an influence of surfactant’s concentration and pH of the micellar mobile phase on the retention of the tested substances was examined. To determine the influence of surfactant’s concentration on the retention of the tested amines, buffered solutions (at pH 7.4) of ionic surfactant—sodium dodecyl sulfate SDS (at different concentrations) with acetonitrile as an organic modifier (0.8/0.2 v/v) were used as the micellar mobile phases. To determine the influence of pH of the micellar mobile phase on the retention, mobile phases contained buffered solutions (at different pH values) of sodium dodecyl sulfate SDS (at 0.1 M) with acetonitrile (0.8/0.2 v/v). The inverse of value of retention factor () versus concentration of micelles () relationships were examined. Other physicochemical parameters of solutes such as an association constant analyte—micelle ()—and partition coefficient of analyte between stationary phase and water (hydrophobicity descriptor) () were determined by the use of Foley’s equation.


Author(s):  
Kishorkumar L. Mule

Objective: To develop and validate new, simple and rapid assay method for Prochlorperazine edisylate drug substance by UPLC as per ICH guidelines.Methods: Ultra performance liquid chromatographic method was developed, optimized and validated on Acquity UPLC by using Acquity BDH300 C4 (100 x 2.1 mm) 1.7µ column. 3.85g ammonium acetate in 1000 ml of water add 0.5 ml trifluoroacetic acid and 1 ml triethylamine (Mobile phase A): 0.5 ml trifluoroacetic acid in 1000 ml acetonitrile mobile phase (Mobile phase B) with gradient program. Detector wavelength 254 nm and column temperature 30 °C.Results: Linearity study was carried out for prochlorperazine edisylate, linearity was calculated from 80 % level to 120% with respect to specification level. The correlation coefficient (r) = 0.999 was proved that the method is robust. The resolution between known impurities and Prochlorperazine edisylate found more than 2.5, it was evident from specificity test that Prochlorperazine edisylate peak are well separated from its related impurities, hence the method is specific. Prochlorperazine edisylate sample solution and mobile phase were found to be stable for at least 3 d.Conclusion: A new, simple and rapid method has been developed and validated for assay determination of prochlorperazine edisylate in drug substance by Ultra Performance Liquid Chromatography (UPLC). The analytical method was developed and validated as per ICH guidelines. The developed method can be used for the fast assay determination of prochlorperazine edisylate drug substances in research laboratories and in the pharmaceutical industry. 


2004 ◽  
Vol 516 (1-2) ◽  
pp. 135-140 ◽  
Author(s):  
José Luis Vı́lchez ◽  
Lilia Araujo ◽  
Avismelsi Prieto ◽  
Alberto Navalón

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