Chapter 10 Column Packing Material and Mobile Phase in Gradient Elution Liquid Chromatography: Practical Aspects

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.


2021 ◽  
Vol 33 (5) ◽  
pp. 1165-1168
Author(s):  
C. Purushotham Reddy ◽  
G. Venkateswara Rao ◽  
K. Ramakrishna ◽  
K.M.V. Narayana Rao

A sensitive and robust high performance liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) method was developed and validated for the determination of potential genotoxic impurity (PGI), 2-(chloromethyl)-3-methyl-4-(2,2,2-trifluoroethoxy)-pyridine hydrochloride (PyCl) in lansoprazole as per ICH Q2 guideline. In this method, PyCl and lansoprazole were well-separated from each other on Acquity UPLC BEH-C18 column (50 × 4.6 mm × 1.7 μ) in a gradient elution mode with the mobile phase consisting of 0.1% formic acid in water (mobile phase-A) and acetonitrile (mobile phase-B) at a flow rate of 0.4 mL/min. For the quantitation of Py-Cl, selective ion monitoring (SIM) mode was used with m/z 240 ion in LC-MS method. The validated method was found to be precise, accurate and linear from the range of LOQ level to 150% with respect to sample concentration and the correlation co-efficient was found to be 0.998. Limit of detection (LOD) and limit of quantifications (LOQ) were found to be 0.000012 and 0.000004 mg/mL, respectively. The validated method was found to be sensitive and the recoveries were found to be well within the range from 83.4% to 95.9% for Py-Cl. Further, the solution stability was also established as the same were found to be stable upto 24 h.


1975 ◽  
Vol 2 (1) ◽  
pp. 1-7
Author(s):  
K J Hauser ◽  
R J Zabransky

Gas-liquid chromatography has become a useful aid for the identification of anaerobic bacteria in the clinical laboratory. When many extracted samples are to be analyzed, time is of prime importance. By altering the operating conditions of the chromatograph, we have decreased the total elution time of the volatile fatty acids examined to approximately 12 min. There is, however, a decrease in the ability to resolve propionic and isobutyric acids. A new column packing material, SP-1220 (Supelco), was found to give excellent separation of propionic and isobutyric acids as well as demonstrating the presence of formic acid which was not seen with the previously used Resoflex. Extracts of clinical isolates of anaerobic organisms were processed using the altered conditions and new column packing material with excellent resolution of all acids. The use of SP-1220 in the clinical laboratory will facilitate the identification of anaerobic bacteria.


Author(s):  
Rayala Rama Rao ◽  
Gundapaneni Ravi Kumar ◽  
Vadde Megha Vardhan ◽  
Veeraswami Boddu

A liquid chromatography with single quadrupole mass detection method was developed for the determination of potential genotoxic impurities (PGIs) in the Iomeprol active pharmaceutical ingredient. Chromatographic separation was achieved on an Agilent Eclipse plus C8 column (100 mm x 2.1 mm x 1.8 μm) with 0.1% formic acid in water as mobile phase A and acetonitrile as mobile phase B in gradient elution mode at a 0.1 mL/min. Executed validation summary demonstrated that the mass detection method had highly sensitive and selective. A linear calibration curve (correlation coefficient, r> 0.999) was attained at the concentration range of 0.1-125 ppm for three PGI’s. The Limit of Detection of Imp-A, Imp-B and Imp-C in drug substance of Iomeprol is 0.05 ppm. The accuracy was confirmed by calculated recoveries (98.4-101.5%). The precision was tested at three levels: injection repeatability, analysis repeatability and intermediate precision. The calculated relative standard deviations were within the specification. The developed method was able to quantitate all three PGI’s at a concentration level of 1 µg/mL.


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