scholarly journals A LC–MS/MS method with column coupling technique for simultaneous estimation of lamivudine, zidovudine, and nevirapine in human plasma

Author(s):  
Srinivasa Reddy ◽  
Licto Thomas ◽  
K. S. Santoshkumar ◽  
Nirmala Nayak ◽  
Arindam Mukhopadhyay ◽  
...  
2019 ◽  
Vol 15 (7) ◽  
pp. 710-715
Author(s):  
S.T. Narenderan ◽  
Basuvan Babu ◽  
T. Gokul ◽  
Subramania Nainar Meyyanathan

Objective: The aim of the present work is to achieve a novel highly sensitive chromatographic method for the simultaneous determination of hepatitis C agents, sofosbuvir and velpatasvir from human plasma using ritonavir as an internal standard. Methods: Chromatographic separation was achieved using Hypersil C18 column (50mm x 4.6mm, 3μm) with an isocratic elution mode using the mobile phase composition 10 mM ammonium formate buffer (pH 5.0): acetonitrile (20:80 v/v) pumped at a flow rate of 0.5 ml/min. The detection was carried out by tandem mass spectrometry using Multiple Reaction Monitoring (MRM) positive Electrospray Ionization (ESI) with proton adducts at m/z 530.10 > 243.10, 883.40 > 114.0 and 721.25 > 197.0. Results: The method validated as per USFDA guidelines with respect to linearity, accuracy, and precision was found to be acceptable over the concentration range of 0.2–2000 ng/ml and 5-2000 ng/ml for sofosbuvir and velpatasvir respectively and the method was found to be highly sensitive and selective. Conclusion: The developed tandem mass spectrometric method is robust and can be applied for the monitoring of plasma levels of the analyzed drug in preclinical and clinical pharmacokinetic studies.


Author(s):  
Aruna G. ◽  
Bharathi K ◽  
Kvsrg Prasad

Objective: To develop and validate a modified isocratic reversed-phase high performance liquid chromatographic (RP-HPLC) method for determination of cilnidipine and nebivolol in human plasma to be used for pharmacokinetic studies.Methods: The drug was extracted from plasma samples by direct protein precipitation technique using acetonitrile. Amlodipine was used as internal standard (IS). Samples were analyzed on BDS C18 column (250 x 4.6 mm, 5 µm), applying ortho phosphoric acid (0.1%): Acetonitrile, at a ratio of 45:55 v/v in isocratic mode as a mobile phase at a flow rate of 1 ml/min to attain adequate resolution. Separations were performed at room temperature and monitored at a wavelength of 260 nm after injection of 50μl samples into the HPLC system. The analytical method was validated according to FDA bioanalytical method validation guidance. The method was applied for pharmacokinetic study of cilnidipine and nebivolol tablets-10 mg and 5 mg were administered as a single dose to 6 healthy male rabbits under fasting condition. Twelve blood samples were withdrawn from each rabbit over 24 h periods. From the plasma concentration-time data of each individual, the pharmacokinetic parameters; Cmax, Tmax, AUC0-t and AUC0-∞ were calculated.Results: A peak area was obtained for cilnidipine and nebivolol at 3.943 and 4.719 min retention time respectively. Linearity was established at a concentration range of 0.20-20 μg/ml (r2=0.999, n=8) for cilnidipine and 0.02-2 μg/ml (r2=0.999, n=8) for nebivolol. The lower limit of quantitation (LLOQ) was identifiable and reproducible at 0.2μg/ml for cilnidipine and 0.02 μg/ml for nebivolol. The coefficients of variation (%cv) of the intra-day and inter-day precision of cilnidipine at 600, 1000 and 1600ng/ml levels were found to be 6.90%, 6.19%, 5.22%; and 7.74%, 6.54%, 5.77%, respectively, which are lower than the accepted criteria limits (15-20 %). The mean recovery (%) cilnidipine at 600, 1000, and 1600ng/ml was found to be 101.03%, 99.27% and 104.87%, and for nebivolol 60, 100, and 160 ng/ml was found to be 106.13%, 107.03% and 98.06% respectively. Stability at different conditions and in autosampler was also established. The mean pharmacokinetic parameters; Cmax, Tmax, AUC0-t and AUC0-∞ were 6 ng/ml, 2 hr, 96.76 mg. hr/ml, 63.45 mg. hr/ml for cilnidipine and 5.8ng/ml, 2hr, 74.78 mg. hr/ml, 100.25 mg. hr/ml for nebivolol respectively.Conclusion: The present analytical method was found to be specific, sensitive, accurate and precise for quantification of cilnidipine and nebivolol in human plasma. It can be successively applied for pharmacokinetics, bioavailability and bioequivalence studies.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Tulsidas Mishra ◽  
Pranav S. Shrivastav

Objectives. HIV protease inhibitors are used in the treatment of patients suffering from AIDS and they act at the final stage of viral replication by interfering with the HIV protease enzyme. The paper describes a selective, sensitive, and robust method for simultaneous determination of three protease inhibitors atazanavir, darunavir and ritonavir in human plasma by ultra performance liquid chromatography-tandem mass spectrometry.Materials and Methods. The sample pretreatment consisted of solid phase extraction of analytes and their deuterated analogs as internal standards from 50 μL human plasma. Chromatographic separation of analytes was performed on Waters Acquity UPLC C18 (50 × 2.1 mm, 1.7 μm) column under gradient conditions using 10 mM ammonium formate, pH 4.0, and acetonitrile as the mobile phase.Results. The method was established over a concentration range of 5.0–6000 ng/mL for atazanavir, 5.0–5000 ng/mL for darunavir and 1.0–500 ng/mL for ritonavir. Accuracy, precision, matrix effect, recovery, and stability of the analytes were evaluated as per US FDA guidelines.Conclusions. The efficiency of sample preparation, short analysis time, and high selectivity permit simultaneous estimation of these inhibitors. The validated method can be useful in determining plasma concentration of these protease inhibitors for therapeutic drug monitoring and in high throughput clinical studies.


Author(s):  
K. S Ashutosh ◽  
D. Manidipa ◽  
R. J. V. L. N. Seshagiri ◽  
S. D. Gowri

The RP-HPLC separation was carried out by reverse phase chromatography on a Symmetry C18 (4.6 x 150 mm, 3.5 μm, make: XTerra) with a mobile phase composed of sodium dihydrogen ortho phosphate [pH 2.5] and acetonitrile in the ratio of 30:70 v/v in an isocratic mode at a flow rate of 1.2 mL/min. The run time was maintained for 8.0 min. The detection was monitored at 236 nm. The accuracy was calculated in human plasma and the % recovery was found 99.80 - 99.85 for famotidine and 99.56 -99.85.5 for ibuprofen and reproducibility was found to be satisfactory. The calibration curve for famotidine in human plasma was linear over 3.32 to 6.65 μg/mL and 100- 200 μg/mL for ibuprofen in human plasma respectively. The inter-day and intra-day precision in human plasma was found within limits. The proposed method has adequate sensitivity, reproducibility, and specificity for the determination of famotidine and ibuprofen in plasma. The LLOQ obtained by the proposed method in human plasma were 1.24 and 5.0 μg/mL for famotidine and ibuprofen respectively. The proposed method is simple, fast, accurate, and precise for the quantification of famotidine and ibuprofen in plasma as per the ICH guidelines.Kathmandu University Journal of Science, Engineering and TechnologyVol. 12, No. I, June, 2016, Page: 34-48


Bioanalysis ◽  
2012 ◽  
Vol 4 (10) ◽  
pp. 1195-1204 ◽  
Author(s):  
D Vijaya Bharathi ◽  
Kishore Kumar Hotha ◽  
Pankaj K Chatki ◽  
V Satyanarayana ◽  
V Venkateswarlu

2008 ◽  
Vol 69 (1-2) ◽  
pp. 9-18 ◽  
Author(s):  
Noel A. Gomes ◽  
Ashutosh Pudage ◽  
Santosh S. Joshi ◽  
Vikas V. Vaidya ◽  
Sagar A. Parekh ◽  
...  

2021 ◽  
Vol 8 (2) ◽  
pp. 201888
Author(s):  
M. M. Tolba ◽  
M. M. Salim ◽  
M. El-Awady

In the present study, we conducted two facile and highly sensitive spectrofluorimetric approaches in order to quantify the vasoprotective agents; troxerutin (TROX) and calcium dobesilate (DOB) in the presence of hydroquinone (HQ) (as a highly toxic impurity and potential degradation product of DOB) in commercial formulations and human plasma. The first approach relies simply on using ethanol as an eco-friendly solvent for the estimation of DOB at 345 nm after being excited at 305 nm. The linearity was carefully investigated between DOB concentration and the relative fluorescence intensity in the range of 0.05–0.8 µg ml −1 . Due to the high method simplicity and sensitivity, applying the first approach to quality control analysis and spiked human plasma samples with mean % recoveries 100.74 ± 3.71 adds another merit. The second approach involved rapid conventional fluorimetric estimation of ethanolic TROX solution in TROX/DOB combined dosage forms at 455/350 nm (emission/excitation) with a linear calibration chart covering the range of 0.1–1.2 µg ml −1 . Moreover, the second approach involved a comprehensive study in a trial to solve the problem of superposition of DOB and HQ graph adopting the first derivative synchronous fluorimetric mechanism in ethanol at Δ λ = 60 nm. Therefore, DOB was measured at 286 and 323 nm, while HQ could be quantitated at 301 nm. The Beer–Lambert Law has complied over the ranges of 0.1–1.0 and 0.02–0.4 µg ml −1 for DOB and HQ, respectively. Guidelines adopted by the International Council of Harmonization (ICH) were used to validate the target approaches. The developed methods are more convenient for routine quality control laboratory instead of the time-consuming and sophisticated reported techniques. Moreover, different aspects of evaluating the greenness of the proposed approaches were conducted to have a complete image of their environmental impact.


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