scholarly journals STABILITY EVALUATION OF CAFFEINE-8-THIOGLICOLIC ACID AMIDES, WITH DETERMINED ANTIHYPOXIC EFFECTS

2017 ◽  
Vol 5 ◽  
pp. 1266-1274
Author(s):  
Javor Mitkov ◽  
Maya Georgieva ◽  
Alexander Zlatkov

This study evaluates a series of caffeine-8-thioglycolic acid amides that were synthesized in the study, for signs of possible degradation. The chemical stability of the test compounds was examined under different conditions of pH and temperature over time. A modified reversed phase-high-performance liquid chromatography method was applied to determine stability and identify possible degradation products. The study identified a new product from oxidative destruction of the test compound through controlled synthesis.

2014 ◽  
Vol 6 (16) ◽  
pp. 6560-6564 ◽  
Author(s):  
Wuxiang Zhang ◽  
Yicong Su ◽  
Jiangu Shi ◽  
Maosheng Zhang ◽  
Bide Wu ◽  
...  

In this paper, a high performance liquid chromatography technique is established for quantification of paraquat in blood.


INDIAN DRUGS ◽  
2021 ◽  
Vol 57 (10) ◽  
pp. 47-57

An isocratic Reversed-Phase High Performance Liquid Chromatography method has been developed for rapid and simultaneous separation and estimation of two antibiotics, namely, nitazoxanide and ofloxacin, in human plasma. Separation was carried out on Altima C8 (150 x 4.6 mm, 5µ) column using a mobile phase of 0.1% ortho phosphoric acid: acetonitrile (50:50, V/V) at 260 nm. The retention time of nitazoxanide and ofloxacin was noted to be 4.850 and 7.949 min, respectively. The average % recovery for nitazoxanide and ofloxacin were 98.012 % and 94.176 %, respectively and reproducibility was found to be satisfactory. The linearity was investigated in the concentration range of 0.02-2 µg/ml (r2=0.9996) for nitazoxanide and 0.008-0.8 µg/ml (r2=0.9998) for ofloxacin. The lower limits of quantification were 0.0196 µg/ml and 0.0079 µg/ml for nitazoxanide and ofloxacin, respectively, which reach the level of both drugs possibly found in human plasma. The proposed method can be applied for etermination of nitazoxanide and ofloxacin from dosage forms during pharmacokinetic study.


2008 ◽  
Vol 30 (3) ◽  
pp. 341-346 ◽  
Author(s):  
Maria Bernadete Sousa Maia ◽  
Ismael Leite Martins ◽  
Demétrius Fernandes do Nascimento ◽  
Adriano Nunes Cunha ◽  
Francisco Evanir Gonçalves de Lima ◽  
...  

Author(s):  
RAMA BUKKA ◽  
CHAYA HN

Objective: The study is aimed to develop a simple, isocratic and sensitive reversed-phase high-performance liquid chromatography method for the analysis of granisetron during transdermal permeation studies through porcine ear epithelium. Methods: A reversed-phase (C18) column was used with ultraviolet detection at 210 nm. Selected mobile phase contained 25% (v/v) of acetonitrile and 75% (v/v) of 0.25 mM potassium dihydrogen orthophosphate solution pH adjusted to 3.0 using 1% orthophosphoric acid solution. Results: Calibration curve showed good linearity over 0.1–30 μg/mL concentration range of porcine ear permeates in 80% ethanol and 20% water (blank permeates). The applicability of the method was demonstrated by the analysis of diffusion study samples of granisetron through porcine ear epithelium and the steady-state permeability flux (J) from ethanolic solution was found to be 4.707 µg/square cm/h. Conclusion: The developed method can be used in the analysis of diffusion study samples of granisetron transdermal formulations through the porcine ear epithelium.


Author(s):  
Mannem Durga Babu ◽  
Kesana Surendrababu

Objective: The objective of the study was to develop and validate a novel, specific, precise, and simple reversed-phase high-performance liquid chromatography method for the estimation of guaifenesin present in methocarbamol API and its pharmaceutical dosage forms. Methods: The baseline separation for methocarbamol and guaifenesin was achieved by utilizing a Inertsil ODS C18 (250 mm × 4.6 mm) 5 μm column particle size and an isocratic elution method. The mobile phase contains a mixture of water and acetonitrile in the ratio of 70:30 v/v, respectively. The flow rate of the mobile phase was 1.0 mL/min with a column temperature of 25°C and detection wavelength at 272 nm. The method was validated for a limit of detection (LOD), limit of quantification (LOQ), linearity, accuracy, and reproducibility with the help of the exhibit and simulated samples. Results: The LOD for guaifenesin was 0.62 μg/mL. The LOQ for guaifenesin was 1.87 μg/mL. The correlation coefficient obtained for impurity was >0.99. The recovery was obtained for impurity was 106.56% at 50%, 95.20% at 100%, and 100.45% at 150%. In tablet analysis, we can found 0.26% (<0.5%). Conclusion: The developed method was validated as per the ICH guidelines with respect to specificity, precision, linearity, accuracy, LOD and quantification, ruggedness, robustness, and solution stability.


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