Chromatography of synthetic and biological polymers. Volume 1 column packing, GPC, GF and gradient elution

Polymer ◽  
1978 ◽  
Vol 19 (12) ◽  
pp. 1478
Author(s):  
A.V. Cunliffe
Author(s):  
Klimenko Lina Yu ◽  
Shkarlat Galyna L ◽  
Shovkova Zoia V ◽  
Yaremenko Vitaliy D ◽  
Shpychak Oleg S

Metronidazole is the most popular representative of antiprotozoal medicines from the group of 5-nitroimidazoles. Metronidazole blocks the enzymes of alcohol dehydrogenase and acetaldehyde dehydrogenase, therefore when its joint taking with alcohol it is observed the strong intoxication syndrome and fatal poisonings too. Therefore metronidazole can be a potential object of chemical toxicological investigations. The purpose of our paper is to develop HPLC/UV-procedure of metronidazole quantification with application of the system of HPLC-analyzer MiLiChrome® A-0230 implemented in practice of forensic medical laboratories in Russia and Ukraine and carry out step-by-step validation of the developed procedure. Chromatographic conditions: Eluent A (0.2 M LiClO4 – 0.005 M HClO4) and Eluent B (acetonitrile) wereused as the mobile phase components; HPLC microcolumn Ø2×75 mm and ProntoSIL 120-5-C18 AQ, 5 μm were used as an analytical column; temperature was 40°С; flow rate was 100 μl/min; gradient elution mode was from 5% to 100% Eluent B for 40 min, then 100% Eluent B for 3 min; detection was performed at 277 nm. Retention time for metronidazole is 5.95 min. Since metronidazole is easy soluble and stable enough in the solutions of diluted alkalis 0.001 M sodium hydroxide solution has been proposed for preparation of the solutions in developing HPLC/UV-procedure of metronidazole quantification. Validation of the procedure has been carried out in the variants of the method of calibration curve and method of standard by such parameters as in process stability, linearity/calibration model, accuracy and precision within 3 different analytical runs using different batches of reagents and different glassware; experiments have been performed by three different analysts. New procedure of metronidazole quantitative determination by the method of HPLC/UV has been developed. Its validation has been carried out and acceptability for application has been shown.


2019 ◽  
Vol 69 (12) ◽  
pp. 3590-3592
Author(s):  
Nela Bibire ◽  
Romeo Iulian Olariu ◽  
Luminita Agoroaei ◽  
Madalina Vieriu ◽  
Alina Diana Panainte ◽  
...  

Active pharmaceutical ingredients such as isoniazid, pyrazinamide and rifampicin are among the most important first-line anti-tuberculosis drugs. A simple, rapid and sensitive reversed phase-high performance liquid chromatographic assay method for the simultaneous determination of isoniazid, pyrazinamide and rifampicin has been developed. Separation of the interest compounds was achieved in a 10 min chromatographic run in gradient elution mode on a Zorbax SB-C18 stainless steel column (150 � 4 mm, 5 mm) using a guard column containing the same stationary phase. The gradient elution was carried out with a mobile phase of 10% CH3CN aqueous solution for channel A and 50% CH3CN in pH = 6.8 phosphate buffer (20 mM), to which 1.5 mL triethylamine were added for channel B. Quantification of the analyzed substances was carried out spectrophotometrically at 269 nm. Detection limits of 0.48 mg/L for isoniazid, 0.52 mg/L for pyrazinamide and 0.48 mg/L for rifampicin were established for the developed assay method. The present work showed that the proposed analysis method was advantageous for simple and rapid analysis of the active pharmaceutical ingredients in pharmaceuticals and biological fluids.


2020 ◽  
Vol 17 (1) ◽  
pp. 47-56
Author(s):  
Shun Liu ◽  
Xun Wang ◽  
Kaiping Zou ◽  
Wei Liu ◽  
Cunyu Li ◽  
...  

Background: Zishen Tongguan (ZSTG) capsules were prepared at the Affiliated Hospital of Nanjing University of Chinese Medicine and have been proven to be clinically effective for treating pyelonephritis and benign prostatic hyperplasia. However, the quality standards are not ideal; a comprehensive study of the “quality markers” (Q-markers), the chemicals inherent in traditional Chinese medicine and its preparations, has not been carried out. Experimental Methods: In this paper, a sensitive and specific ultra-high-performance liquid chromatographictandem mass spectrometry (UHPLC-MS/MS) method was developed for the simultaneous determination of eight potential Q-markers of ZSTG, including timosaponin A3, berberine, jatrorrhizine, phellodendrine, palmatine, mangiferin, neomangiferin, and timosaponin BII. A Kromasil 100-3.5 C18 column was used with a mobile phase of 0.2% formic acid with acetonitrile, and gradient elution at a flow rate of 0.2 mL/min was achieved in 13 minutes and used for separation. Detection was performed in positive/negative mode with multiple reaction monitoring (MRM). Results: The analytical method was validated in terms of the sensitivity, linearity, accuracy, precision, repeatability, stability and recovery. The method established here was successfully applied to study the potential Q-markers in 8 batches of commercial samples, which demonstrated its use in improving the quality control of ZSTG. Conclusion: The developed method had high repeatability and accuracy and was suitable for the simultaneous analysis of multiple Q-markers, which may provide a new basis for the comprehensive assessment and overall quality control of ZSTG.


2020 ◽  
Vol 16 (7) ◽  
pp. 831-843
Author(s):  
Yuwen Wang ◽  
Shuping Li ◽  
Liuhong Zhang ◽  
Shenglan Qi ◽  
Huida Guan ◽  
...  

Background and Objective: Kang Fu Xin liquid (KFX) is an official preparation made from the ethanol extract product from P. Americana. The present quality control method cannot control the quality of the preparation well. The aim of the present study is to establish a convenient HPLC method for multicomponents determination combined with fingerprint analysis for quality control of KFX. Methods: An HPLC-DAD method with gradient elution and detective wavelength switching program was developed to establish HPLC fingerprints of KFX, and 38 batches of KFX were compared and evaluated by similarity analysis (SA), hierarchical clustering analysis (HCA), and principal component analysis (PCA). Meanwhile, six nucleosides and three amino acids, including uracil, hypoxanthine, uric acid, adenosine, xanthine, inosine, tyrosine, phenylalanine and tryptophan in KFX were determined based on the HPLC fingerprints. Results: An HPLC method assisted with gradient elution and wavelength switching program was established and validated for multicomponents determination combined with fingerprint analysis of KFX. The results demonstrated that the similarity values of the KFX samples were more than 0.845. PCA indicated that peaks 4 (hypoxanthine), 7 (xanthine), 9 (tyrosine), 11, 13 and 17 might be the characteristic contributed components. The nine constituents in KFX, uracil, hypoxanthine, uric acid, adenosine, xanthine, inosine, tyrosine, phenylalanine and tryptophan, showed good regression (R2 > 0.9997) within test ranges and the recoveries of the method for all analytes were in the range from 96.74 to 104.24%. The limits of detections and quantifications for nine constituents in DAD were less than 0.22 and 0.43 μg•mL-1, respectively. Conclusion: The qualitative analysis of chemical fingerprints and the quantitative analysis of multiple indicators provide a powerful and rational way to control the KFX quality for pharmaceutical companies.


2019 ◽  
Vol 15 (5) ◽  
pp. 505-510
Author(s):  
Yanjuan Zheng ◽  
Qiushi Peng ◽  
Rui Dong ◽  
Tingyu Chen ◽  
Yi Bao ◽  
...  

Introduction: A rapid, and accurate Ultra Performance Liquid Chromatography (UPLC) method was developed to simultaneously analyze Methocarbamol, Paracetamol and the related substances Materials and Methods: Waters ACQUITY UPLC® BEH Phenyl C18 column was used in conjunction with UV detection at 225nm. Gradient elution with 0.05M, pH 6 phosphate buffer and acetonitrile flow at 0.3mL /min rate were used to separate the substances. The retention times for 4-Aminopheno, Paracetamol, Guaifenesin, Methocarbamol, and 4-Chloroacetanilide were 1.319 minute, 2.224 minute, 4.467 minute, 4.769 minute and 5.433 minute respectively. The concentration was linear in the range of 2-100 µg/ml for Methocarbamol, and 1-100 µg/mL for Paracetamol. The percentage recoveries were between 99.28±1.23% to 100.57±0.99% for Methocarbamol, and between 99.08±1.23% to 101.23±1.39% for Paracetamol. Results and Discussion: The validated optimal protocol is robust and accurate for simultaneous analysis of Methocarbamol, Paracetamol and the related substances, applicable for bulk powder as well as pharmaceutical formulation. Conclusion: In this paper, a highly sensitive, accurate, and precise UPLC method with UV-Vis detection was developed and validated for quality control of MET and PAR in bulk as well as in pharmaceutical preparations.


2019 ◽  
Vol 16 ◽  
Author(s):  
Joanna Wittckind Manoel ◽  
Camila Ferrazza Alves Giordani ◽  
Livia Maronesi Bueno ◽  
Sarah Chagas Campanharo ◽  
Elfrides Eva Sherman Schapoval ◽  
...  

Introduction: Impurity analysis is an important step in the quality control of pharmaceutical ingredients and final product. Impurities can arise from drug synthesis or excipients and even at small concentrations may affect product efficacy and safety. In this work two methods using high performance liquid chromatography (HPLC) were developed and validated for the evaluation of besifloxacin and its impurity synthesis, with isocratic elution and another with gradient elution. Method: The analysis by HPLC in isocratic elution mode was performed using a cyano column maintained at 25 °C. The mobile phase was composed by 0.5% triethylamine (pH 3.0): acetonitrile (88:12 v/v) eluted at a flow rate of 1.0 ml/min with detection at 330 nm. The gradient elution method was carried out with the same column and mobile phase components only modifying the rate between organic and aqueous phase during analysis. The procedures have been validated according to internationally accepted guidelines, observing results within acceptable limits. Results: The methods presented were found to be linear in the 140 to 260 µg/ml range for besifloxacin and 0.3 to 2.3 µg/ml for an impurity named A. The limits of detection and quantification were respectively 0.07 and 0.3 µg/ml for impurity A, with a 20 µL injection volume. The precision achieved for all analyses performed provided RSD inter-day equal to 6.47 and 6.36% for impurity A with isocratic elution and gradient, respectively. The accuracy was higher than 99% and robustness exhibited satisfactory results. In the isocratic method an analysis time of 25 min and 15 min was obtained for gradient. For impurity A, the number of theoretical plates in the isocratic mode was about 5000 while in the gradient mode it was about 45000, hence, it made the column more efficient by changing the mobile phase composition during elution. In besifloxacin raw material and in pharmaceutical product used in this study, other related impurities were present but but impurity A was searched for and not detected Conclusion: The proposed methods can be applied for quantitative determination of impurities in the analysis of the besifloxacin raw material, as well as in ophthalmic suspension of the drug, considering the quantitation limit.


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