scholarly journals A Modified Method for Determination of Lumefantrine in Human Plasma by HPLC-UV and Combination of Protein Precipitation and Solid-Phase Extraction: Application to a Pharmacokinetic Study

2010 ◽  
Vol 5 ◽  
pp. ACI.S4431 ◽  
Author(s):  
Liusheng Huang ◽  
Patricia S. Lizak ◽  
Anura L. Jayewardene ◽  
Florence Marzan ◽  
Ming-Na Tina Lee ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Human Plasma ◽  
Solid Phase ◽  
Internal Standard ◽  
Pharmacokinetic Interaction ◽  
Gradient Elution ◽  
Protein Precipitation ◽  
Phase Extraction ◽  
Modified Method

An HPLC-UV method was developed and validated for the determination of lumefantrine in human plasma. Lumefantrine and its internal standard halofantrine were extracted from plasma samples using protein precipitation with acetonitrile (0.2% perchloric acid) followed by solid-phase extraction with Hypersep C8 cartridges. Chromatographic separation was performed on a Zorbax SB-CN HPLC column (3.0 × 150 mm, 3.5 μm) with water/methanol (0.1% TFA) as the mobile phases in a gradient elution mode. Detection was performed using UV/vis detector at λ = 335 nm. The method showed to be linear over a range of 50-10,000 ng/mL with acceptable intra- and inter-day precision and accuracy. The mean recoveries were 88.2% for lumefatrine and 84.5% for the I.S. The internal standard halofantrine is readily available from commercial sources. This method was successfully applied to a pharmacokinetic interaction study between a first-line antimalarial combination (artemether—lumefantrine) and antiretroviral therapy.

scholarly journals Determination of Ranitidine in Human Plasma by SPE and ESI-LC-MS/MS for Use in Bioequivalence Studies

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Karini B. Bellorio ◽  
Maria Isabel R. Alves ◽  
Nelson R. Antoniosi Filho
Keyword(s):  
Solid Phase Extraction ◽  
Human Plasma ◽  
Extraction Method ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Internal Standard ◽  
Phase Extraction ◽  
Good Separation ◽  
Limit Of Quantification

A method for determining ranitidine in human plasma by ESI-LC-MS/MS was validated, using propranolol as internal standard. The extraction method used was solid phase extraction (SPE). Chromatographic separation was performed in a Chromolith C18 (50 mm × 4.6 mm i.d.) analytical column, which provided good separation of ranitidine and propranolol peaks with an analysis time of 2.5 minutes. Extraction yields of 94.4% for ranitidine and 89.4% for the internal standard were obtained. The lower limit of quantification (LLOQ) was 3.00 ng/mL, and limit of detection (LOD) was 0.05 ng/mL, with linearity ranging from 3.00 to 500 ng/mL. The results, thus, showed that this method is suitable for application in bioequivalence studies of ranitidine in human plasma.

scholarly journals Simultaneous determination of azathioprine and its metabolite 6-mercaptopurine in human plasma using solid phase extraction-evaporation and liquid chromatography–positive electrospray tandem mass spectrometry

2012 ◽  
Vol 1 (11) ◽  
pp. 342-352 ◽  
Author(s):  
Mokkaisamy Jegadeesh Raja ◽  
Jegadeesh Raja Kavitha ◽  
Kothamasu Pavan Kumar ◽  
Thangavel Sivakumar
Keyword(s):  
Liquid Chromatography ◽  
Solid Phase Extraction ◽  
Human Plasma ◽  
Solid Phase ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Pharmaceutical Journal ◽  
Tandem Mass ◽  
Phase Extraction

A simple, rapid, specific, sensitive and liquid chromatography coupled with tandem mass spectrophotometric method was developed and validated for the estimation of azathioprine and its metabolite 6-mercaptopurine in human plasma by using lamivudine and 6-mercaptopurine D3 as the internal standard. Azathioprine and 6-mercaptopurine were extracted from human plasma by solid-phase extraction (SPE)-Evaporation method, using Oasis MCX cartridge for cleaning procedure. The stationary phase was chromatographed on a ZORBAX SB CN, (75X50 mm, 5 µ) column where as mobile phase constitutes of acetonitrile: 2mM ammonium acetate (70:30 v/v) at a flow rate of 0.800 ml/min. The detection was performed with an Applied Biosystems Sciex API 4000 mass spectrometer by multiple reaction monitoring (MRM). The method validation proofs were carried out as per the USFDA guidelines as described, showing a linearity system (r2 > 0.99) over a range of 2.455 ng/mL to 106.568 ng/mL for azathioprine and 1.165 ng/mL to 101.143 ng/mL concentrations for 6-mercaptopurine and a recovery shows 99.36% and 100.44% for azathioprine and 6-mercaptopurine respectively. The results show that this proposed approach is effective and can be applied to the extraction and analysis of other pharmaceutical compounds.DOI: http://dx.doi.org/10.3329/icpj.v1i11.12059 International Current Pharmaceutical Journal 2012, 1(11): 342-352 

Sign in / Sign up

Export Citation Format

Share Document